Summary:
This resolves lots of double escaping.
We changed most of `phutil_render_tag(, , $s)` to `phutil_tag(, , $s)` which means that `$s` is now auto-escaped.
Also `pht()` auto escapes if it gets `PhutilSafeHTML`.
Test Plan: None.
Reviewers: epriestley
Reviewed By: epriestley
CC: aran, Korvin
Maniphest Tasks: T2432
Differential Revision: https://secure.phabricator.com/D4889