Add the possibility to use regular expressions for the makeplist stage of the PLIST_SUB life.

[mat]

Summary

From time to time, the values are too generic, and they get in the way of other stuff.

This adds the possibility to have a VAR_regex=regex that will be used instead of the VAR=string to search for possible replacements.

For example, build lang/perl5-devel, then:

root@10amd64-ports-perl5-devel:/usr/ports/lang/perl5-devel # touch `make -V STAGEDIR`/usr/local/lib/perl5/5.25/mach/foo
root@10amd64-ports-perl5-devel:/usr/ports/lang/perl5-devel # touch `make -V STAGEDIR`/usr/local/lib/machine

Without the patch, it will do:

root@10amd64-ports-perl5-devel:/usr/ports/lang/perl5-devel # make check-plist
====> Checking for pkg-plist issues (check-plist)
===> Parsing plist
===> Checking for items in STAGEDIR missing from pkg-plist
Error: Orphaned: lib/%%PERL_ARCH%%ine
Error: Orphaned: %%ARCH_LIB%%/foo
===> Checking for items in pkg-plist which are not in STAGEDIR
===> Error: Plist issues found.
*** Error code 1

Stop.
make: stopped in /usr/ports/lang/perl5-devel

With it will do a more correct version:

root@10amd64-ports-perl5-devel:/usr/ports/lang/perl5-devel # make check-plist
====> Checking for pkg-plist issues (check-plist)
===> Parsing plist
===> Checking for items in STAGEDIR missing from pkg-plist
Error: Orphaned: lib/machine
Error: Orphaned: %%ARCH_LIB%%/foo
===> Checking for items in pkg-plist which are not in STAGEDIR
===> Error: Plist issues found.
*** Error code 1

Stop.
make: stopped in /usr/ports/lang/perl5-devel

[bdrewery]

Works for me, so long as it still works everywhere. This is hard to review. I was hoping for a more automatic solution but this is fine for now.

[bdrewery]

If somehow we could use \<word\> or [[:<:]]word[[:>:]] that would be nice