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
Fix overflow problem introduced in the #406 bugfix (scrolling is missing)
add migration script for thread->references
Merge branch 'displayer-unification' into develop
shadow sheet, don't shadow paper
restore full white background
update annotator to 1.2.6-dev-e0acf62

fixes #409
closes #410
minor annotator update 1.2.6-dev-e661e78

smooths last difference between the jquery and pure dom xpath
upgrade to angular v1.1.4
better fix for #405 that doesn't break animation
get XSRF-TOKEN from cookies as a fallback

This is helpful, for example, in an extension setting where newer
versions fo angular don't send the X-XSRF-TOKEN header on CORS
requests. In this case, if the request is with credentials, we
can still get it from the cookie.

Should fix login from the extension.
ensure a csrf token exists even on xhr app

This helps with the extension, where no request to /app for the
HTML content type exists.
Fixes #419
Fixes #418
Fixes #418
remove unnecessary highlight css transition
don't change the highlight text color

fixes double-text on highlights in PDFs
whitespace