https://github.com/CocoaPods/CocoaPods/pull/2153#issuecomment-43617235

This reverts commit 5e74184a.

Closes https://github.com/CocoaPods/CocoaPods/issues/2154

Trunk

https://github.com/CocoaPods/CocoaPods/issues/2151\#issuecomment-43493702\

https://github.com/CocoaPods/CocoaPods/issues/2151\#issuecomment-43493702

The guide has a lot more info, and mentions Rainforest.

[Sources] Use `git pull` with the `--ff-only` flag

This fixes issue where since we were using `--no-commit`, git was
starting a merge but not committing it. Then subsequent `git pull`'s would
result in the following error from git:

> You have not concluded your merge (MERGE_HEAD exists).
> Please, commit your changes before you can merge.

This commit will mean that `--ff-only` is passed to `git pull`  which means
it wont rebase or merge. It will only allow a fast forward to progress
with the pull.

Fixes #2024

I'm sure everyone is going to hate me for doing this.

Fixes #1771
Closes #1966

Try to detect and remove local paths from error messages when generating...