Revert caffe-0.13 branch

[lukeyeager]

Reverting all changes in master from caffe-0.13 so we can merge changes from caffe-0.14.

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I wanted to do this upgrade (1) while preserving commit history for public commits, (2) without force-pushing to any public branches and (3) with a single revert commit. The git command was pretty hairy. I ended up with this after following this SO post:

git commit-tree \
  $(git merge-base HEAD nvidia/caffe-0.14)^{tree} \
  -p $(git rev-parse HEAD) \
  -m "Revert caffe-0.13 branch" \
  | xargs git merge

Don't ask me to explain it all, but now we can do a git merge nvidia/caffe-0.14 (with no merge conflicts) to sync master with caffe-0.14.

[lukeyeager]

Alternatively, we could delete the master branch entirely and make caffe-0.14 the new default branch.

https://help.github.com/articles/setting-the-default-branch/

[lukeyeager]

Alternatively, we could delete the master branch entirely and make caffe-0.14 the new default branch.
https://help.github.com/articles/setting-the-default-branch/

After some testing, here would be the consequences of deleting master and setting caffe-0.14 as the master branch:

1. git pull would throw a strange error if you had the master branch checked out:

   Your configuration specifies to merge with the ref 'master'
   from the remote, but no such ref was fetched.

2. Old clones wouldn't be switched over to the new branch automatically - they would need to re-clone or git checkout caffe-0.14 to switch to the new version.

3. remotes/origin/HEAD would not be updated automatically to the new default branch and would throw this warning because master is missing - (refs/remotes/origin/HEAD has become dangling). It's not a problem, but you could resolve it with this command: git remote set-head origin --auto.

(1) and (3) would only appear with this release because we'd be deleting the master branch - in future releases we won't need to delete any branches.

For the next release, we would start development on caffe-0.15 (or maybe nvcaffe-0.15) and change the default branch from caffe-0.14 to caffe-0.15 when we go to public RC. We would of course leave the old release branches around.

I think we should do it because it matches our development flow and is a more reasonable solution than manually keeping two branches in sync (which is what we currently do).

[borisfom]

Let's not delete the master branch.
Merging caffe-0.14 into the master is the right idea.