* floor should compile on windows/mingw now (including support for the intel, amd and nvidia opencl sdk and cuda)
 * don't use -m32/-m64 flags on mingw (the compiler/linker already now these and cross-compiling won't work and isn't supported anyways)
 * added opencl and cuda sdk handling to the build script (for mingw), note that the path handling is slightly awkward (I don't know how to properly escape this, so specify it directly when calling clang when linking)
 * link libsupc++ (needed for cxxabi) and winsock2 (needed for networking) on windows/mingw
 * define BOOST_USE_WINDOWS_H on windows/mingw (won't work at all otherwise)
 * some define documentation
 * undef VOID and CONST in essentials.hpp (defined by windows)
 * killed off some windows platform code (don't include any windows headers, get rid of pragmas, kill strtof and getcwd), windows/msvc isn't supported anyways right now, but this will work with mingw now
 * include the net/net_protocol.hpp header prior to any other windows headers (boost will include the winsock2 api, but windows headers would include version 1, which obviously won't work out)
 * removed -Wno-unknown-pragmas flag from mingw build again