- Style fixups in the code.
- map<> serialization fixes and more tests.
- Autocreation of map<> fields (to match repeated fields).
- @@protoc_insertion_point(global_scope|imports).
- Fixup proto2 syntax extension support.
- Move all startup code to +initialize so it happen on class usage and not app startup.
- Have generated headers use forward declarations and move imports into generated code, reduces what is need at compile time to speed up compiled and avoid pointless rippling of rebuilds.

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.

Re-add the objc prefix that got removed by accident.
Regenerate the generated descriptors (C++ and ObjC).