Getting the ObjC generator building on Windows.

Remove the ClassList support (maybe bring it back in the future).
Trim the includes to hopefully get a working Window build.
Add some more returns after switches for compilers that warn even when all values of the enum are handled.
Use ghtonl instead of htonl.
Change the use of [u]int(8,32)_t within the ObjC generator code to [u]int(8,32) to match the rest of the compiler.
Add objective-c generator files to Visual Studio project.