R1:83bbad8ba0d6

Move skins toward modularization

Summary:
Two high-level things happening here:

- We no longer ever need to put meta-UI (content creation, editing, notices, etc.) on live blog views, since this is all in Phame now. I pulled this out.
- On the other hand, I pushed more routing/control logic into Skins and made the root skin a Controller instead of a View. This simplifies some of the code above skins, and the theory behind this is that it gives us greater flexibility to, e.g., put a glue layer between…