[WIP] Edit SH5 zone files in S3D

Getting ready for the next patch,
I knew I'd loath useing Goblin for doing the zon files.
So today I did a bit of work on the
SH3ZonesCtrl.cs
used by S3D.

I can now work the zon files with S3D.
It needs a bit of tweaking to finish and I've asked
skwasjer for advice and his permission to release
once it's completed.

But so far it works like a charm!