Support for UIKitForMac on Xcode 11

[jlubeck]

Trying to compile the library for UIKitForMac on the new Xcode 11 is throwing a couple of errors.

Just thought I'd open the ticket. I'll try to make a PR when I get a chance, unless someone else makes it first

Thanks!

[lwdupont]

Ah, thanks for the heads up! I might have some time this afternoon to take a look at it, but don't let that prevent you from fixing it and doing a PR :) We appreciate any help.

And frankly glad to hear at least someone is still using it. Sometimes it's hard to tell. :)