Bug fix: the implementation method should be from the build fact, but not the original call
In current_called_from, also MGoal is filtered by IM, provided that IM is instantiated, and if not, it is instantiated to the IM of MGoal
Minor bug fix in location_utils.pl
Minor bug fix in check_unused.pl
Fixed minor bug in implementation_module usage, when the head or module are
uninstantiated
- Saving check-unused without group with adjacency/4, to allow proper differences
  and avoid false-positives when comparing differences between results.