Code: WinMain required for Windows version

As of 0f307cfc code has been mostly adjusted for Windows compatibility without adding any major additional pieces. Trying to compile it though results in linker error pointing to a lack of WinMain function which seems to be required for GUI application support on Windows. Plan is to prototype some code with stubby WinMain to get the grasp of it and then decide if we need to keep separate main.cpp files for platforms (although I'd like to avoid that) or separate common parts to separate file and then keep two definitions or maybe WinMain is going to be a separate thing just for Windows GUI support. We'll see, this thread shall be for documenting progress and notekeeping