Summary:
This opens up the new action column to have specialized rendering and behavior. Briefly:
- Converted applications (right now, only Paste) render a `CurtainView` to build the column content.
- This view uses new extensions to build panels (projects, subscribers, tokens).
- The panel extension code and rendering can be changed without breaking old stuff.
Minor changes:
- Token awards now load their tokens, for consistency/simplicity.
- Removed the rest of the "fork of" / "forked from" UI in Paste -- I essentially removed these features a while ago, and no one has complained.
Test Plan:
UI is a bit rough, but works, and it's going to get changed now anyway:
{F1160550}
{F1160551}
Reviewers: chad
Reviewed By: chad
Differential Revision: https://secure.phabricator.com/D15414
