Tidy up argument parsing in release email script
External_auth.views.login_or_signup fix codepath that didn't set uname

which caused UnboundLocalError.  Added tests for this case
fix to problems with uploading files
Fix saving notification CSS.
Merge pull request #379 from edx/peter-fogg/fix-notification-saving

Fix saving notification CSS.
Added in a retry for checking the class of the video
Made a new command css_has_class that will safely check the class and get around stale elements
Refactored LMS so all potential stale element exceptions are avoided
CMS acceptance tests now should not get stale element exception errors
Fixed structure of css_text and css_value
Reworded css_text to use css_find
Revert "Reworded css_text to use css_find"

This reverts commit a7de337fe2d218d6cb9c2f175c6ea71f5ddcb6da.
Changed a world.browser.find_by_css to world.css_find
Made a retry_on_exception world function that will retry the given function
Refactored the ui tests to use retry_on_exception
Refactored problem_setup to use retry_on_exception
Refactored recently merged in tests
Fix alt text for the login page: LMS-600
Added documentation to new acceptance test features and techniques
vagrant: Always mount `node_modules` folder after Vagrant NFS mount