Implemented basic point light shader
(AKA per-fragment/per-pixel Phong shading)

Renamed shaders to more appropriate names
Refactored Rasterizer GLSL module

For Programs, using cfg instead of p for file extension
For Shaders, using glsl instead of vert/frag/etc for file
extension
Use relative file path to cwd for keys for shaders and
programs
Replaced shader subclasses with shader classmethods
Renamed program_name to program_cfg
Revised Contributing section of documentation
Refactored GLEW and X11 C bindings

Implemented GLEW compute and tessellation shader bindings
(GL_ARB_compute_shader, GL_ARB_tessellation_shader)

Added back commented out defines to glew.h for clarity;
these defines are wrapped with functions instead of
being used directly

Removed glewInit2

Implemented GLX bindings

Implemented FFI including properly

Moved X11 GLX user code to GLEW GLX
Using bindings aliases - string and new - instead of
directly from FFI