Turn group reg on

Turns group reg on in configspec and sets the relevant dates.
Add band ribbons back in

The lack of BAND_RIBBON in constants.py broke group reg.
Fix badges_to_add

Fixed the error where uber tried to pull a variable from the session.
Fix adding group badges

Last fix to let people add group badges - making sure the register time
is set.
Merge pull request #463 from magfest/85_group_reg

Fix group reg for 8.5