muggins/ST4-ObjC2.0-Runtime

This is the first commit of compileable source for the ObjC2.0 Runtime framework for ST4.
The source is totally untested. Many of the early decisions in the translation need to be reviewed in light
of what I learned as the process of translation proceeded. There are many warning messages in compiling,
some probably represent serious issues.

Don't even expect this code to run at this point.