Make -filter argument take a regex

[jevinskie]

The big ask here is to make -filter take a regex.

I also did some yak shaving and modernized the Obj-C a bit. You can take it or leave it. If you want that, I can certainly split it up into a different commit/PR.

If you're keen on this filter regex feature, let me know and I'll fixup this PR to remove my code signing changes (and split/remove the Obj-C updates if you wish). I'm just a bit lazy and didn't want to do that work now unless you're interested in the regex feature.