Fixes #6117 - clean usergroup cache

Dependent destroy was missing on through association from user side.
fixes #6116 - search hosts by parent host group and its decendants
fixes #6112 - log/test.log disappears when running under spork
fixes #6091 - menu removal wasn't traversing menu hierarchy
fixes #5652 - run parse_args when calling new_vm for compute profiles
fixes #5708: #nil? is now an allowed method inside of Host and Token jails