Fix help modal css selector
Remove antiquated cleanup script

This script was originally written to clean up XML scripts. In the more
than two years since it was originally written, the only updates it has
received have been to remove PEP8/PyLint/quality violations.

It's hard to imagine that this is still useful to anyone, though I'm
open to discussion.
config refactor wip
merging from master
Uncomment thumbnail tests
Decorate test functions that require Pillow JPEG support
actually look for an image to verify that a thumbnail has been generated
Update pillow to 2.6.1
pep8 and comments
Moved has_course_access from CMS to student.auth (common)
Change has_course_access definition and doc string

- has_course_access renamed to has_course_author_access for clarity
- Changed doc string to clearly state that it determines whether or not
  a user has write access to a course
Split mongo support for libraries and Library XBlock
renmaing prod.py and setting more defaults
Remove extra prerequisites style and add classes
renaming to use underscores
Add compare-branch option to paver run_quality
Fixed plus sign icon for overall grade range add button.
TNL-890
Merge pull request #6143 from edx/waheed/tnl890-fix-plus-sign-overall-grade-range

Fixed plus sign icon for overall grade range add button.
Don't allow voting while the thread is closed

When someone closes thread there is still option
to add vote which cause error when click on add
vote button. User shouldn't be able to add vote
while the thread is closed.

TNL-152
Merge pull request #6064 from Stanford-Online/kluo/quality-compare-branch-option

Add compare-branch option to paver run_quality