Sort library directories in LibraryBrowser3
Merge pull request #458 from paulvojta/develop

Sort library directories in LibraryBrowser3
Chage color.js to use class names rather than explicit colors.
Update color.js to color ans_array and MultiAnswer answer blanks when singleResult is 1.
Reformatting Problem number labels on gateways to be heading and added aria navigation markup.

Changed 'prewview answers' to 'preview my answers'

other stuff
Made further improvements
 - The gateway results table has been redone as a pure data table.  It looks more like the Problem results table
 - The grades table has been redone to improve accessibility by adding columns.
 - Add due date in title on Problem Set view
 - Added aria labels to show achievement percentage.
Polished upgrade script and made error message for missing columns more helpful
Upgraded aria labels to work correctly with multianswers, as well with quizes and multianswers and matricies and multianswers.
Merge branch 'patch-input-colors' of http://github.com/dpvc/webwork2 into access

Conflicts:
	htdocs/js/legacy/color.js