Removed TODO
Added new package. Added OpenGL Exception Class.
Added simple (and naive) Shader implementation.
Updated ALL special Blocks to fix raytracing bug.

Detailed Explanation: Before the bug-fix, if a player was in survival
mode, he could not open a door if it was behind a invisible special
block (like the trigger-block). The fix only affects the
collisionRaytrace() method, by including a check for creative-mode.
Compiled new build artifact!