Bring "fixes x as y" parser forward and use new parsers instead of old ones

Summary: Fixes T3872. Ref T1812. Ref T3886. Modernize the "closes x as y" string parser, and use all the new parsers instead of the old ones.

Test Plan: Made a commit full of a pile of these trigger strings, then used scripts/repository/reparse.php --message to reparse it. Verified that parses came back as expected using a bunch of var_dump().

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1812, T3872, T3886

Differential Revision: https://secure.phabricator.com/D8263