v12 support

[cpcodes]

I know this is a bit early to make this request, but considering the new Scene Regions in v12, I think that much of the work is now done by the system, merely needing a few tweaks to integrate into the existing UI and I wanted to put the bug in your head to consider using them rather than updating the region code used in the module. As close as the built-in capability comes to a full implementation, I half expected the core team to throw manual FOW in as a surprise feature late in development, but as we rapidly approach release, it now seems unlikely.

Anyway, thought I'd suggest it. I'm not familiar with any of the code, so it could very well be that implementation with scene regions is infeasible for reasons I'm unaware of, in which case this is just an embarrassingly early reminder to update for v12.

Thanks for maintaining such an essential tool!

[jasonxbergman]

I'm holding off on upgrading until simplefog supports v12. Hopefully it can be done!