Pre-prepare for hovercards
Summary:
D5120 and followups refactor and generalize object references in Remarkup -- notably, they move remarkup rules from a central location to the implementing applications.
Preserve blame by doing moves/renames only first. This change moves application remarkup rules into those applications, and renames the ones D5120 modifies.
Test Plan: Typed some preview text into a textarea, got a valid Remarkup render.
Reviewers: vrana, chad
Reviewed By: vrana
CC: aran
Differential Revision: https://secure.phabricator.com/D5123