Summary:
Allow skins to serve arbitrary resources without needing to be mapped, so we can have a vibrant community of amateur skinners.
For "basic" skins, just put all the "css/" on the page always.
Includes an image to prove that works.
@vrana, pretty sure this has no impact outside of Phame but it does change Celerity so it might be to blame if there's any weirdness with static resources.
Test Plan:
{F21341}
{F21340}
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T1373
Differential Revision: https://secure.phabricator.com/D3719
