Added a lot of notes to the TODO about various materials and processes.
Starting to think that kind of info should get a separate notes file.
Also added material information for blocks.

-Peter Mawhorter
Updated the makefile to include new object files and got things
compiling again.

-Peter Mawhorter
More work on geology during worldgen.

-Peter Mawhorter
Got things into a semi-working state (they compile) but the world
generation (not to mention chunk generation) is slow. Will have to start
profiling this next.

-Peter Mawhorter
Lots of graphics work, as a result of running valgrind and finding that
my shader code was ignoring some OpenGL errors (now it ignores
fewer... ...). Switched from GLEE to GLEW for the extensions support
past OpenGL 3.0, but my configuration doesn't currently support geometry
shaders, so instead of figuring that out I just disabled them for now
(they weren't going to be efficient in any case I think).

The switch from GLEE to GLEW made me overhaul my OpenGL checking file,
so it's now a real .c file instead of just a .h file to be compiled with
-E.

Also some progress on worldgen; slowly fixing bugs and speeding things
up there. Added a layer of B_BOUNDARY to the bottom of the world.

Also improved texture loading: if a texture fails to load, it doesn't
keep trying every frame.

-Peter Mawhorter
Got things working in a very technical sense of the term. Chunk
construction using strata was able to produce layers of stone, but not
nearly in real-time. Several methods of optimization will be necessary.

-Peter Mawhorter