Remove regex usage from places that don't need it

In revwalk, we are doing a very simple check to see if a string
contains wildcard characters, so a full regular expression match
is not needed.

In remote listing, now that we have git_config_foreach_match with
full regular expression matching, we can take advantage of that
and eliminate the regex here, replacing it with much simpler string
manipulation.
Clean up newly introduced warnings

The attempt to "clean up warnings" seems to have introduced some
new warnings on compliant compilers.  This fixes those in a way
that I suspect will also be okay for the non-compliant compilers.

Also this fixes what appears to be an extra semicolon in the
repo initialization template dir handling (and as part of that
fix, handles the case where an error occurs correctly).