workshops.views: Edit awards in the person-detail edit view.

Using django-extra-views to automatically deploy the inline formsets
[1].  To handle the datepicker stuff, you need my widgets addition
[2].  I hope that lands soon (it's a simple change), but there are a
number of older issues and pull-requests in that repository, so I'm
not sure how active the upstream maintainer is.  If we get tired of
waiting for a release, we can for the library and depend on our fork,
but I'd rather avoid that if possible.

The datepicker widgets are from bootstrap-datepicker via the data-api
instantiation [3].

This commit also tweaks the person-detail display to show a person's
current awards.

[1]: https://pypi.python.org/pypi/django-extra-views/
[2]: https://github.com/AndrewIngram/django-extra-views/pull/93
[3]: https://bootstrap-datepicker.readthedocs.org/en/release/#data-api
workshops.urls: Add 'POST /workshops/event/{slug}/award'

To automatically create awards based on an event.  It's useful for
badging organizers (and once we have a badge for them and a list of
actual attendees, for badging students).  I'm not sure about badging
instructors this way.  The current implementation does badge
instructors for the event that weren't already badged, but maybe we
want to reserve badging for folks completing the instructor training
course (regardless of whether or not they've been an instructor at an
event)?  In that case we'd want to tie the instructor award creation
to setting Person.trainee.status to the 'completed' status.  We may
also want to distinguish badging logic based on Event.project (SWC,
Data Carpentry, ...).

I've removed the HttpResponseRedirect import because we don't use it
since the last reference was removed in 4e211e12 (First working
version of instructor lookup form, 2014-12-16).