Write documentation

[3b]

• translate official GL docs into some easier format (or figure out docbook), updating types with lisp types from %GL: bindings if possible
• add versions of translated docs for things wrapped in GL: package, updated for any automatic translations or whatever
• document any GL: features that don't correspond directly to the low-level GL API
• describe general idea of when and how to use %GL: directly
• add lisp example code, or links to example code in repo? (at least for more interesting parts of core profile)
• document automatic error checking and how to disable it
• info on GLU/GLUT?

[TeMPOraL]

I second the "document automatic error checking and how to disable it" point. It should be prominently visible.

I just run into a serious performance bottleneck caused by repeat calls to glGetError() on a virtual machine (VirtualBox) running Ubuntu 14.04. Adding #:cl-opengl-no-check-error to *features* and rebuilding cl-opengl solved the issue.