Add event stream utility class for Backbonization of EventSource.
Add a notification model and a progress subtype for it
Add notification stream implementation on the server
Merge remote-tracking branch 'origin/master' into event-stream
Fix web client tests hanging
Use UTC timestamps in model layer

MongoDB (sensibly) always operates in UTC, and we should too for
consistency. Clients will be responsible for coercing timestamps
to the user's timezone when rendering them.
FIX ALL OF THE TESTS!!! (>'-')>  <('-'<)
Add a progress context manager

This is used to rate-limit progress update writes to the database
and provide convenient semantics for callers to easily manage
progress.
Merge remote-tracking branch 'origin/master' into event-stream

Conflicts:
	clients/web/test/spec/collectionSpec.js
Make sure SSE channels close when server is shutting down
Changed the default api endpoint security to require admin access.  Each handler should be decorated with @admin, @user, or @anonymous to override the default (the default is the same as specifying @admin).

I have attempted to pick the right value for all of the endpoints, but it would be handy to have someone else review my choices.  I have removed some of the admin and user checks that would now be duplications of what the decorators do.  Some of the tests have changed, since the error messages are not necessarily the same.

I modified the existing loadmodel plugin to better presrve the function name using the functools.wraps function.  If we wanted to ensure that decorated functions and methods looked even more like their original functions, I'd recommend pulling in the decorator module with pip; this isn't required, but it makes some debugging of decorated functions and methods easier.
Changed @anonymous to @public.
Fix docstring typo from long ago.
Move ProgressContext into a submodule of utility package
Place access decorators into girder.api.access
Fixes #363. Delete token from db on logout
Merge branch 'api-access-decorators' into event-stream
Fix cyclomatic complexity in test base class
Finish backend infrastructure for progress
Implement progress reporting on folder recursive delete