Migrate the "badcommit" table to use the less-hacky "hint" mechanism
Summary: Ref T11522. This migrates any "badcommit" data (which probably only exists at Facebook and on 1-2 other installs in the wild) to the new "hint" table.
Test Plan:
- Wrote some bad commit annotations to the badcommit table.
- Viewed them in the web UI and used bin/repository reparse --change ... to reparse them. Saw "this is bad" messages.
- Ran migration, verified that valid "badcommit" rows were successfully migrated to become "hint" rows.
- Viewed the new web UI and re-parsed the change, saw "unreadable commit" messages.
- Viewed a good commit; reparsed a good commit.
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T11522
Differential Revision: https://secure.phabricator.com/D16435