Summary: Ref T4189. Fixes T2066. Mercurial has a //lot// of hooks so I'm not 100% sure this is all we need to install (we may need separate hooks for tags/bookmarks) but it should cover most of what we're after at least.
Test Plan:
- `bin/repository pull`'d a Mercurial repo and got a hook install.
- Pushed to a Mercurial repository over SSH and HTTP, with good/bad hooks. Saw hooks fire.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T2066, T4189
Differential Revision: https://secure.phabricator.com/D7685
f93c6985ad