Revert "OpenGL-ES converstion"

This reverts commit 70eef55ab58313312d7f3468c6457b72f6694239.

It was premature to merge this commit into HEAD. Maybe we'll try again
one day, but only if a complete and fully working patch with build
system integartion is provided.
Use the correct abs() flavor
A comparision "array != NULL" is always true