Add normal mapping example

CMakeLists.txt

demos/CMakeLists.txt

demos/NormalMapping/.gitignore

demos/NormalMapping/CMakeLists.txt

demos/NormalMapping/shaders/NormalMapping.frag

demos/NormalMapping/shaders/NormalMapping.vert

demos/NormalMapping/shaders/Phong.frag

demos/NormalMapping/shaders/Phong.vert

demos/NormalMapping/src/main.cpp

framework

resources/brick.png

resources/cubeMap/negx.jpg

resources/cubeMap/negy.jpg

resources/cubeMap/negz.jpg

resources/cubeMap/posx.jpg

resources/cubeMap/posy.jpg

resources/cubeMap/posz.jpg

resources/cubeMap/readme.txt

resources/cv_logo.png

resources/normalmapping/diffusemap.png