Summary:
Based on orionr's work

 - [x] Solve [the problem about GenerateProposals](https://github.com/facebookresearch/Detectron/pull/334#issuecomment-378764468)
 - [x] Use the existing [ResizeNearest](https://github.com/caffe2/caffe2/blob/master/caffe2/operators/resize_op.cc#L57) layer instead of UpsampleNearest. ResizeNearest has cpu implementation and neon optimization
 - [x] Make it work (with https://github.com/pytorch/pytorch/pull/7091)

With this PR, FPN is supported in cooperation with https://github.com/pytorch/pytorch/pull/7091. I have verified that it works on `e2e_faster_rcnn_R-50-FPN_1x.yaml`
Pull Request resolved: https://github.com/facebookresearch/Detectron/pull/372

Reviewed By: newstzpz

Differential Revision: D9213242

Pulled By: rbgirshick

fbshipit-source-id: 8fc7b77e6cbf08adaafd760505dd760df59bfd79

Reviewed By: rbgirshick

Differential Revision: D9133758

fbshipit-source-id: a698a637b294b7f2aef4c181cb47505187be3935

Summary:
AFAIK, this is what the rest of the codebase does. I don't want to
see logger.debug() messages show up during normal runs.

Differential Revision: D9071531

fbshipit-source-id: 4ac5ef57ee47bf958e35d723c379f695554f0ef0

Summary: Fix typo

Reviewed By: newstzpz

Differential Revision: D9065042

fbshipit-source-id: 6e5bb566813febcb21c0c26afe429e2dc7a3eefc

Reviewed By: ir413

Differential Revision: D9014510

fbshipit-source-id: a1320b1c221546ad795a94dce254e9520a0847fd

Reviewed By: rbgirshick

Differential Revision: D8836361

fbshipit-source-id: f7d8bad14e0d6309ae349616f2b837d7082e2d74

Summary:
Add TRAIN.COPY_WEIGHTS (default False):

When setting True, training will copy TRAIN.WEIGHTS to checkpoint folder and treat it as a candidate checkpoint. This is useful if we want to resume a checkpoint from another job (instead of using ImageNet pre-training).

Reviewed By: rbgirshick

Differential Revision: D8710711

fbshipit-source-id: 9c011227867c52eaaeb40e3c2679cff1cfccdc66

Summary:
- Added command line argument to infer_simple.py to choose a custom output image format.
- Added command line argument to infer_simple.py to choose to output an image even when no object is found in it.
Closes https://github.com/facebookresearch/Detectron/pull/400

Reviewed By: ir413

Differential Revision: D8705039

Pulled By: rbgirshick

fbshipit-source-id: fbcd707821a58004971a88946a17f005545ecab4

Summary: Closes https://github.com/facebookresearch/Detectron/pull/515

Reviewed By: ir413

Differential Revision: D8704635

Pulled By: rbgirshick

fbshipit-source-id: d68d89d31c886d00a66ef7d95909eb7ebc1db9fb

Summary: Closes https://github.com/facebookresearch/Detectron/pull/511

Reviewed By: ir413

Differential Revision: D8704693

Pulled By: rbgirshick

fbshipit-source-id: c05064ab69c795f8b3263fc0b35ddb666019cd5f

Summary:
Correct the `test_batch_permutation_op.py` and `test_spatial_narrow_as_op.py` link.
Closes https://github.com/facebookresearch/Detectron/pull/527

Reviewed By: rbgirshick

Differential Revision: D8677148

Pulled By: ir413

fbshipit-source-id: ce8898f48590b57ed964db113035fb4da8418668

Reviewed By: rbgirshick

Differential Revision: D8614301

fbshipit-source-id: 384df17bebd0a0186a0867cf16a7a7dfea5646ae

Reviewed By: rbgirshick

Differential Revision: D8541427

fbshipit-source-id: f681d75ad77ea0c7411e5c6099c6bb0c2497d571

Summary: change _DEPCRECATED_KEYS -> _DEPRECATED_KEYS

Differential Revision: D8553498

fbshipit-source-id: 1431a9552efce47be3aa40718c954521481950de

Summary: Update from-scratch results in GN/README.md, given the freeze_at=0 fix.

Reviewed By: ir413

Differential Revision: D8369007

fbshipit-source-id: a7df13364125dac09379c5aed647f4f9a8bbf23b

Summary:
Move freeze_at to config.

Fix GN from-scratch scripts with freeze_at=0.

Reviewed By: rbgirshick

Differential Revision: D8325882

fbshipit-source-id: 9f362cb269ffd962056dfe8adc888083cff3d9b2

Reviewed By: rbgirshick

Differential Revision: D8332717

fbshipit-source-id: a3070cd83855b5c91a3395d8bbe6c4a70774a1b9

Summary: Remove code that seems redundant.

Reviewed By: rbgirshick

Differential Revision: D8200163

fbshipit-source-id: c3096c77a1c6b33eab5dc0ceb9414f3bdbbf71e9

Summary: The arg name has been changed by this diff: D7857548

Reviewed By: rbgirshick

Differential Revision: D8283673

fbshipit-source-id: 961dc3773ce7b49d67874323a6dfef738538036d

Summary:
I found that the json annotations for Pascal VOC downloaded from the [URL](https://storage.googleapis.com/coco-dataset/external/PASCAL_VOC.zip) in [detectron/datasets/data/README.md](https://github.com/facebookresearch/Detectron/blob/master/detectron/datasets/data/README.md#pascal-voc-annotations-in-coco-format) are split into three sets: 'train', 'val' and 'test'.
Therefor, it's unable to use 'trainval' set directly.
For example, the code can't found the 'voc_2007_trainval.json' file when using the following configure:
```python
TRAIN:
  DATASETS: ('voc_2007_trainval',)
Closes https://github.com/facebookresearch/Detectron/pull/299

Differential Revision: D8202450

Pulled By: ir413

fbshipit-source-id: 8d8bc8ce406b2d2ed4af57953846d21fa1968018

Summary: Fix a bug of aspect ratio grouping to support training batch size > 2.

Reviewed By: rbgirshick

Differential Revision: D8157964

fbshipit-source-id: 28eec6246cd6daf83aef30da245fe7bf340fbbc9

Summary:
Dilation value `cfg.MRCNN.DILATION` is only used to calculate padding for conv, but not assigned to the dilation argument of conv.
Closes https://github.com/facebookresearch/Detectron/pull/388

Reviewed By: rbgirshick

Differential Revision: D8160945

Pulled By: ir413

fbshipit-source-id: dca6a5cf7659f29a5d1d91e860c9dfff4963e7c3

Reviewed By: rbgirshick

Differential Revision: D8117250

fbshipit-source-id: 1cd6e033c3ed3057afeeb92ed86a20d807549b5a

Reviewed By: rbgirshick

Differential Revision: D8117130

fbshipit-source-id: e75dd34c9748a17432fffe792f7a0871e09e2797

Reviewed By: rbgirshick

Differential Revision: D8116895

fbshipit-source-id: 6d8b5be01189db16ec92c8b5b0010db810777170

Reviewed By: rbgirshick

Differential Revision: D8113057

fbshipit-source-id: 36ea85bb0e0f2a9f253c96cca5fd7f148b6746ab

Reviewed By: ir413

Differential Revision: D8083267

fbshipit-source-id: 96c17d79d117bf434a5b879a8bca4c88ea6b68e2

Summary:
We fix some typos: lib -> detectron .
Closes https://github.com/facebookresearch/Detectron/pull/429

Reviewed By: rbgirshick

Differential Revision: D7988278

Pulled By: ir413

fbshipit-source-id: 5e673b51a831f95aa7d7ea2ce51c5c41a1715825

Summary:
For RoIFeatureTransform Methods with ArgMax (RoIPoolF/RoIPoolLateQuantization), the current pipeline will report
```
TypeError: I/O blob #0 of unsupported type: (BlobReference("gpu_0/roi_features"), BlobReference("gpu_0/_argmax_roi_features")) of type <type 'tuple'>
```
as in the example training: https://our.intern.facebook.com/intern/fblearner/details/51149202/

Reviewed By: viswanathgs

Differential Revision: D7907518

fbshipit-source-id: 38caa51c955f5a577d11c04688b9061cb6dd3c22

Reviewed By: rbgirshick

Differential Revision: D7774100

fbshipit-source-id: e11d30fd817c8553ac6f2de16924eea3f78c8814

Reviewed By: rbgirshick

Differential Revision: D7516523

fbshipit-source-id: 7c67f82c7ce6f79a66b0bdea0770d2d00735e38f

Summary:
Fixed "cannot find cmake/Cuda.cmake" error when executing "make ops" command (the correct path is cmake/legacy/Cuda.cmake")
Closes https://github.com/facebookresearch/Detectron/pull/399

Reviewed By: rbgirshick

Differential Revision: D7790070

Pulled By: ir413

fbshipit-source-id: 6fc49b226be227dc8e9e638a9f4c39ef2efc22aa

Reviewed By: rbgirshick

Differential Revision: D7513510

fbshipit-source-id: cf46a61f8e1e9f81154fc43974be5abc4afec2f4

Summary:
This basically allows Detectron to be built without having to include the many cmake files from Caffe2. Caffe2 now properly exports utility functions and dependent libraries, and so one can use the new style targets "caffe2_library" and "caffe2_gpu_library" directly.

This should also solve problems like #251 after we update the conda version. cc pjh5.
Closes https://github.com/facebookresearch/Detectron/pull/286

Reviewed By: ir413

Differential Revision: D7397696

Pulled By: Yangqing

fbshipit-source-id: 7a47e0addedd4b3c88dd8e2e130afdad04706acc

Summary: fix a typo in url

Reviewed By: ppwwyyxx

Differential Revision: D7746833

fbshipit-source-id: a0873424ef91625d67f3fbfe44d2b1c5c9c8a4b8

Summary: Add GN documentation.

Reviewed By: rbgirshick, ppwwyyxx

Differential Revision: D7745878

fbshipit-source-id: 8a49160b1e4026fbcf41082df4a3a8d0f8e90d85

Summary: Add GroupNorm support to master Detectron.

Reviewed By: rbgirshick

Differential Revision: D7611892

fbshipit-source-id: dc4fb84a0e2167b05fd8a94ee0ff1ab1c21369b7

Summary:
Before this change <code>assert_and_infer_cfg</code> would override the weights passed by the user with CFG ones.

It is normal to change it as the user is required to pass weights, otherwise there will be this error :
<code>AssertionError: <class 'NoneType'></code>. (verified only in infer_simple.py)

Sort of follow-up of eddb1301.
Closes https://github.com/facebookresearch/Detectron/pull/331

Reviewed By: ir413

Differential Revision: D7569224

Pulled By: rbgirshick

fbshipit-source-id: 00dbaadd2440f39b2b3440b4101a58ed3e68a908

Reviewed By: rbgirshick

Differential Revision: D7491769

fbshipit-source-id: 20d8d1f72a773379a3882b697b574b0b0b4f01d3

Reviewed By: rbgirshick

Differential Revision: D7484464

fbshipit-source-id: f92804fedc3ae040e585e7c0c2eb3e44526eef22