MinGW support updates

Omnibus MinGW support patch: Updates to MinGW hacks block in CMakeLists. Updates to GLEE glue/exceptions in PolyGLHeaders, PolyGLSLShaderModule, PolyWinCore. Remove redundant gl includes in PolyWinCore.cpp. Include <ios> explicitly in windows PolycodeView. Omit multitouch support (code in PolycodeView, TUIO module) when compiling with MinGW. All targets other than MinGW+Windows should remain unchanged after bringing in these changes because everything's behind #ifdefs.