remove displayer.css and unify w site mostly

- Use the reify decorator to cache results of expensive Store calls
  made during displayer rendering.
- Re-work the displayer to have annotations more like the threading
  on the client. In other words, pass the whole annotation, not just
  the fields in the the displayer.
unused variables and white space
more unused variables
add migration script for thread->references
Merge branch 'displayer-unification' into develop