Bugfixes

This is the pull request to bugfix 2.9 and will be pulled just before 2.9 is released.  You should use this branch to test things, and put any bugs you found below. For starters

-  Removed the Reduced Credit Date changes to pg since those are in develop and not 2.9 for WeBWorK.   Note:  This was done using git revert, which makes new commits to revert the changes.  This is probably the best way, but its likely to also revert changes if we pull this back into develop.  Any ideas on the proper way to handle this Davide?