Fix Visual Studio build by not setting CUDA_PROPAGATE_HOST_FLAGS to OFF

Solution: don't set CUDA_PROPAGATE_HOST_FLAGS to OFF when using Visual Studio

using train_one_step(), you will get the behavior of automatic disk syncs at
the end of training.

partial C++11 support and funny cmake behavior of clang on OS X.

to new versions of clang on OSX, without this extra statement C++11 wasn't
being enabled.

map_output_to_input() in the concat_ layer.

Add MKL DFTI FFT bindings.

Apparently, MKL installations don't always include header files. So
detect MKL libraries and headers seperately.