Support pushing data into Git LFS
Summary:
Ref T7789. Ref T10604. This implements the upload action, which streams file data into Files.
This makes Git LFS actually work, at least roughly.
Test Plan:
- Tracked files in an LFS repository.
- Pushed LFS data (git lfs track '*.png'; git add something.png; git commit -m ...; git push).
- Pulled LFS data (git checkout master^; rm -rf .git/lfs; git checkout master; open something.png).
- Verified LFS refs show up in the gitlfsref table.
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T7789, T10604
Differential Revision: https://secure.phabricator.com/D15492