glew-cmake release from glew-2.2.0

Documentation updates for GLEW 2.2.0 release

glew-cmake release from glew-2.1.0

glew-cmake release from glew-2.0.0

glew-cmake release from glew-1.13.0

glew-cmake release from glew-1.12.0

glewinfo fixup for MacOS core context mode with version>4.0+

README.md updates for GLEW 2.0.0 release

Bump version to 1.13.0, updated documentation.

Bump version to 1.12.0, updated documentation.