Remove extra newlines from preformatted blocks
Split renderer into a separate jar.

renderer-src contains the transitive dependency closure for the renderer
- but this resutls in rather a lot of classes (more than expected), so
  the next task is to try to refactor to reduce this.
Implement a SimpleWikiUrls interface, providing just what the renderer needs, and move the rest of the WikiUrls stuff back to wiki-src
Implement a test PageStore, move other PageStore stuff to wiki-src
Implement SimpleAttachmentHistory and SimplePageStore interfaces to move more VC stuff to wiki-src
Rename TestPageInfo to TestVersionedPageInfo and move to wiki-src
Move fix.text.Strings to wiki-src
Remove unneeded imports
Add extra tests for the renderer registry