initial files and changes
Removed userstamp gem. Still lots of test failures.

Added userstamp gem's functionality into project directly.
Almost have all tests passing...
need to clean up abilities.rb - don't use :manage, how to check nested :index ?
Changed AudioEventComments and Bookmarks completely to new API Spec.

Added jbuilder templates for comments and bookmarks.
Added controller helper for common api functionality.
Added render_fields to filter_settings for default projection.
Added resposne_index method on Api::Response so that the ACtiveRecord::Relation is available.
Abilities rearranged - they make sense finally.
added more Permissions tests; fixed some Ability ambiguities
only one annoying test left to resolve!
Userstamp tidy up, last fixes for tests failures.

Removed last remnants of userstamp gem in migrations.
changed filter to use implicit 'and'.
fixed last failing tests
Merge branch 'annotation_discussions_take_2' into develop

Bringing feature branch into develop.