Summary:
This is very preliminary and doesn't actually do anything useful. In theory, it uses Drydock to check out a working copy and run tests. In practice, it's not actually capable of running any of our tests (because of complicated interdependency stuff), but does check out a working copy and //try// to run tests there.
Adds various sorts of utility methods to various things as well.
Test Plan: Ran `reparse.php --harbormaster --trace <commit>`, observed attempt to run tests via Drydock.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T2015, T1049
Differential Revision: https://secure.phabricator.com/D4215
