* Remove custom styles for groups since we're using default Bootstrap
  styles now.
* Hidden input breaks grid layout. Moved it inside the groups column.
* Removed unnecessary 'groups' and 'members' classes. They are not being
  used in JS nor CSS.

Remove unittest-specific callbacks for checking access and displaying
the calendar events on the dashboard.

This will allow plugin developers unittest the full behavior
of how their plugins add events to the dashboard.

Reset all static caches between unittests.

The core_group_get_activity_allowed_groups WS should be returning not
only the groups but also if the user is allowed to access all the
activity groups.