Flag submissions from staff grading view

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...

Feature/valera/video alpha

Firefox doesn't draw the buttons right with -90deg, but will draw it right if no direction is specified.

700x sandbox

allow "rows" attrib of coderesponse textbox to set box height

Fixed bugs. Removed unnecessary things from HTML5. Minor improvements. Subtitles now work in HTML5 if specified.