CMake version of glad loader

Using OpenGL 4.6 and all EXT and ARB extensions. You can change the output directory by setting GLAD_CUSTOM_OUTPUT and then setting GLAD_CUSTOM_OUTPUT_DEBUG, GLAD_CUSTOM_OUTPUT_RELEASE and so on to the specific paths.

Licence Notice: Only CMake files are made by me. Source and Header files were generated using Dav1dde's OpenGL loader generator.