Fix error message provided by Instructor dashboard datadump - make it more useful

xmodule scss - resolved studio bug #191

Skip self assessment test (fails due to need for querydict for getlist t...

Skip self assessment test (fails due to need for querydict for getlist to work, but mocking querydict is painful)

Omit migrations from code coverage reports.

Also omit portal and terrain, which are used for the lettuce testing framework.

Feature/vik/improve oe ui

xmodule scss - resolved some general span styling that would override basic em or strong type styling

Soft Landing UI, Studio Nav Revamp, Sign In/Up Revisions

Flag submissions from staff grading view

Merge branch 'feature/btalbot/studio-softlanding' of github.com:MITx/mitx into feature/btalbot/studio-softlanding

Merge branch 'feature/btalbot/studio-softlanding' of github.com:MITx/mitx into feature/btalbot/studio-softlanding

Feature/marco/addcomponent

:-(

Bugfix/valera/video alpha

add exporting of policy.json

fix module staff accesss - by has_access, not by user.is_staff

Better logging, and make view csrf exempt...

Feature/victor/foldit api

  - ops view for the desktop app to talk to
  - xmodule that talks to the foldit model and displays the student's state
  - grading tweak to make grade updates from an external service work:
    - Add an always_recalculate_grades property to XModuleDescriptor.

Firefox doesn't draw the buttons right with -90deg, but will draw it rig...