Write a very basic string extractor

Summary: Ref T1139. This has some issues and glitches, but is a reasonable initial attempt that gets some of the big pieces in. We have about 5,200 strings in Phabricator.

Test Plan: {F108261}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran, chad

Maniphest Tasks: T1139

Differential Revision: https://secure.phabricator.com/D8138
Disallow "{", "}" and "#" in Project monograms

Summary: Currently, mentioning two projects in a block (`{#a} {#b}`) produces an overzealous parse. Forbid these characters in project monograms.

Test Plan: Got correct markup.

Reviewers: btrahan, dctrwatson, chad

Reviewed By: chad

CC: aran

Differential Revision: https://secure.phabricator.com/D8141
Merge branch 'master' of http://github.com/facebook/phabricator