* add prolog/swipl linter
* use load_files/2 instead of read_term/2
Because it also checks some semantic warnings / errors
not only syntactic warnings / errors.
e.g.:
* singleton warning
* discontiguous warning
* ...
cf. http://www.swi-prolog.org/pldoc/doc_for?object=style_check/1
* support error messages with no line number
:- module(module_name, [pred/0]).
causes
ERROR: Exported procedure module_name:pred/0 is not defined
* add test for prolog/swipl handler
* cosmetic fixes
* detect timeout using SIGALRM
* rename g:prolog_swipl_goals to g:prolog_swipl_load
* write doc for prolog/swipl linter
* update toc and README
* fix ignore patterns
