* Altered consistency checks to treat any root as equivalent
  (so, if you're project_root in the default group, but group_root in
   a group, that won't be a problem)

* Moved consistency checks, which were done in two different places into
  dbdefs TBCheckGroupTrustConsistency()

* Added preemptive checks, so if 'user' or '*_root' are not valid
  trusts, they aren't displayed as options in editgroup_form and
  approveuser_form (using above function)

* In approveuser, a new approval may now be sent to group_root.