a49138defd
Summary: This thing services every app but it lives inside Differential right now. Pull it out, and separate the factory interfaces per-application. This will let us accommodate changes we need to make for Phriction to support wiki linking. Test Plan: Tested remarkup in differential, diffusion, maniphest, people, slowvote. Reviewed By: hsb Reviewers: hsb, codeblock, jungejason, tuomaspelkonen, aran CC: aran, hsb Differential Revision: 646