Force charset for application.sass to be UTF-8

refactor tests, add test for is_commentable_cohorted, fix a bug

Feature/victor/cohorts

Returns None if course isn't cohorted, even if cohorts exist.  Shouldn't happen on prod, but could if cohorting is turned off mid-course.

Conflicts:
	common/djangoapps/student/models.py

Add a .ruby-version file for use w/ rbenv

fix bug in video player:if from=xx:xx:xx is used then bkgrnd flashes

Pearson export/import code. (No merging before 25th Jan)

caveat: with a bit of hackery.  Need to do better testing once things are live.

min height on droppable areas and add padding to top/bottom on hover.

unit/subsection/section drag and drop on overview page

Added one more year!

- we don't use it, and if we do want to change the arch, we should have a proper central user info service.

racing condition.

put back the 'position' argument to get_module() which got accidentially...

put back the 'position' argument to get_module() which got accidentially - or so I think - dropped in a previous commit

- this may not be a good idea, but needed for testing cohorts for now...