Cmake update and remove old scripts from build folder

CMake: be more robust and also tell us what we are building for

@walzer This should be a good start to making a first installable package for cocos2d-x
We have /lib/libcocos2d.a
Now we just need includes in /include/
It is not needed for audio/CMakeLists.txt
I have also set it up in a manor to inherit so that would be declaring it twice