This leads to much simpler error checking. Add casts so the inlined code can be called from the editor's C++ code.
This is mostly just nit-pickery that allows most of the editor to be compiled with MinGW. The nasty COM-stuff for the XML-loader in syncdocument.cpp is still not compiling, though. There's also some missing resource definitions, it seems.
Make sure that all code included in the player and client is pure C. This helps on portability.
