Docblock parser for AT

Summary: Some obnoxious regex stuff.

Reviewed By: @elgenie

Differential Revision: D1691746

Signature: t1:1691746:1416484124:59952412946da18bd1106bfd479d155b7138ac2b
Have hh_server take the list of files to recheck as relative paths

Reviewed By: @jwatzman, @elgenie

Differential Revision: D1690037

Signature: t1:1690037:1416451135:4dda91e120000c477a8ecdb8170190748c4b3627