Once again, massive changes.

* Okay, first off, I went and renamed a ton of methods to conform to my
newly preferred naming style.
* Got rid of the separate cursor rendering program and merged it into
one big renderer.
* SFML is throwing some strange GL_INVALID_OPERATION errors when it
tries to bind the font texture, so for the time being I've disabled the
GUI.  I want to start handling textures myself, anyway, so no big harm.
* I've also rewritten the renderer so lighting is directional instead of
point-based.  Or maybe I did that on the last commit.  I forget now.

Next up... reworking the chunk rendering routine to cut down on
unnecessary vertices.  Bonus: it'll make the chunks look far more
Lego-like which fits well into my vision.