GNU Prolog should use the GNU standard format for errors

[Stefan Monnier]

I have GNU Prolog 1.2.18 here (Debian package) and errors in my source code
are reported using the following format:

   | ?- ['exp.pl'].
   compiling /some/where/exp.pl for byte code...
   /some/where/exp.pl:62 error: syntax error: . or operator expected after 
expression (char:2)
   /some/where/exp.pl:66 error: syntax error: . or operator expected after 
expression (char:48)
   /some/where/exp.pl:68 error: syntax error: . or operator expected after 
expression (char:2)
   /some/where/exp.pl:78 error: syntax error: , or ) expected (char:33)
   /some/where/exp.pl:95 error: syntax error: . or operator expected after 
expression (char:2)
        5 error(s)
   compilation failed

I think this should be changed to follow the GNU coding convention which
recommend the use of formats such as <file>:<linenb>:<text> or
<file>:<linenb>.<columnnb>:<text>.

The change should be minor and would bring much better integration with
generic IDEs such as Emacs.


        Stefan