Fixed already solved problem in perform_substitution and added a test to avoid it reappear
Minor format improvement with lists
Including the extra character nl in the boundaries of a comment, if it start with %
Minor bug fix in prolog:xref_open_source
Unify File only if it is uninstantiated
Less fail prone
Hack to avoid refactorization at the same position more than once
Updated gcb test
b_getval--->nb_current in prolog:xref_open_source/2
Fixed write_tail/3, was not working properly for empty lists
Minor bug fix in ref_replace:term_write_stop_nl, sometimes the tail is not a []
Fixed do_r_goal_expansion/2, prolog_load_context/2 does not work properly in such place, using refactor_file context variable instead.
Fixed rename_predicate, was not working properly
Removed now unused predicate
Merge remote-tracking branch 'origin/master' into fixing-substitutions

Conflicts:
	prolog/ref_replace.pl
More fixes