Fixed some issues with the timedatepicker functionality.  In particular time zones are no loger hard coded.
Removed inintended warn
Update default_achievements.axp

Fixed some spelling errors
Modified datetimepicker so that it doesn't constrain what people can type.
Merge pull request #144 from goehle/datetimefix

I took another look at everything and had a friend do some testing.  Everything looks OK so I'll merge.
Backported fix for Visible/Reduced Credit Enabled checkboxes always being marked.
Fixed bug 2708 by commenting out tikz option
Merge pull request #148 from goehle/hotfixes

Backport fixes
Merge branch 'master' of http://github.com/openwebwork/webwork2 into mathviewbackport