Improved record locations to allow saving position of :-/1 goals and conditionals
Improved precision in called_from and check_unused, using new functionality of record_locations
declaration goals should be ignored
Only record callable declaration goals
Cosmetic changes
- Renamed record_location_term/1 to record_term_location/1.

- Using system:term_expansion/4 and system:goal_expansion/4 instead of
  user:term_location/2 and user:goal_expansion/2.
Including predicate indicator in implemented_in messages
Added module_class/1 option to prolog codewalker