fixed errors associated with deleting users as well as importing users from a file.
A message wasn't being shown on adding a user.
Fixed errors associated with loading user manually.
Merge branch 'ww3' of https://github.com/openwebwork/webwork2 into ww3-feature/fix-classlist

Conflicts:
	webwork3/public/js/apps/CourseManager/CourseManager.js
fixed an error with the rendering the side pane
Changed the text on a button.
Fixes an error where a CSV file with no suffix doesn't trigger an error message to the user.
Merge branch 'ww3' of https://github.com/openwebwork/webwork2 into ww3-feature/fix-classlist

Conflicts:
	webwork3/public/js/apps/CourseManager/CourseManager.js
Added .csv to exporting a classlist file.
Merge pull request #367 from pstaabp/ww3-feature/fix-classlist

Ww3 feature/fix classlist

The file has a csv extension now.