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
Add tests for changing table status without staff permissions.
add export_all_courses management script to cms
fix two typos in export scripts
Fix alt text for the login page: LMS-600
add extra modulestore() argument to export to make it export drafts also
add extra modulestore() argument to single export script
Added documentation to new acceptance test features and techniques
vagrant: Always mount `node_modules` folder after Vagrant NFS mount
Adding myself to authors file
Merge pull request #333 from edx/jonahstanley/fix-flakey-video-test

Jonahstanley/fix flakey video test
Beginnings of refactoring the acceptance tests
All lms acceptance tests refactored to use world dictionaries
CMS now refactored to use world dictionary
Scenario Dictionary now holds objects