Merge branch 'develop' of https://github.com/hypothesis/h into 514-simple-tagging-4
Separated the directives into two separate modules

This was necessary because some of them must be made available
for the displayer page, and possibly other pages, too,
but some other directives depend on annotator, which is only present
in the main app.

Therefore, no we have
 - the h.directives angular module for the small, independent directives, and
 - the h.app_directives angular module, which currently only holds the
   annotation directive.
Show tags on displayer page, too
Display tags on user stream page, too
Merge branch '514-simple-tagging-4' of https://github.com/hypothesis/h into 514-clickable-tabs
Added trivial filter to decode spaces in URIs
Add tags and title to tagstream
Added title to user stream page