Build broken on Windows 10 using CMake

[programadorthi]

moai-dev/src/moai-core/MOAILuaRuntime.cpp

Line 829 in b01816f

return ( this->mState != 0 );

This above line I did fix changing to call: return this->mState.IsValid(); because is the same logic.

moai-dev/src/moai-sim/MOAIFrameBuffer.cpp

Line 63 in b01816f

self->mGrabNextFrame = self->mFrameImage != 0;

This above line I did fix changing for the code below. I didn't know if it is correct but it works:

MOAILuaSharedPtr< int > empty;

self->mGrabNextFrame = self->mFrameImage != empty;

moai-dev/cmake/cmake/third-party/sdl2/CMakeLists.txt

Line 5 in b01816f

set (SDL2_SOURCE_DIR "${MOAI_ROOT}/3rdparty/sdl2-2.0.4")

The SDL2 third-party is using version 2.0.4 but there is 2.0.9 in submodules folder only. Changed to 2.0.9 line 5 and line 11 works.

moai-dev/src/zl-gfx/ZLGfxDevice.cpp

Line 127 in b01816f

if (( isOpenGLES == false ) && ( majorVersion < 3 )) {

This variable majorVersion is not declared in the class. I changed to sMajorVersion.

I didn't make a pull request because I don't know if these changes are correct.