Put shader sources into their own files

A header file will be processed by CMake which will contain shader
sources as string constants.
Merge pull request #2 from rthome/shaderfiles

Put shader sources into their own files
Group GLSL and Cmake-processed files into their own IDE folders
Add empty files for noise generator
Merge branch 'noise' of https://github.com/rthome/CubeDemo into noise