More bugfixes

• Fixed not being able to open Mailing list view.
• Solved a problem where saving tag groups could cause onCourse to hang.
• Fixed a problem where link icons meant to open up Contact edit screens were not working.
• Fixed a problem with the class by subject report. The max column was not correct.
• Prevented an exception message when opening the session view.
• When limited acces roles were granted to view class info, would result in graphical glitches where information could not be read. This has been fixed.