Improve regular expressions to handle cases with :#:# in the code

When looking at references I sometimes have results like

    file:line:col   code("hi:4:5");

which messes up parsing since the regular expressions for the file are greedy.  Anyway, I changed them to be non-greedy and that has fixed my problems.  They could probably be changed to use `\S *` instead of `.*` for the file component, but this change was smaller and less likely to break something.

I looked through the rest of the elisp briefly.  I think `rtags-goto-location` and `rtags-taglist` are probably okay as is.  I don't understand the context of `rtags-filename-complete` and `rtags-find-file` well enough to judge.  I don't think there were any others.