Added .gitignore, new Makefile, and testing methodology

New Makefile incorporates a separate source file for testing individual
routines.
test.s just outputs a “hello, world” string by default.
Added chunky font as an include

Standard chunky-style font. Nothing special to see here. Move along.
Removed commented line in `make test` from Makefile.
Simplify, simplify

Removed lots of unnecessary stuff to get to the basics of the game loop
/ startup
More radical simplification

Working towards a bare-bones template that works (i.e. will draw the
Capn on screen). Explicated how sprites work in comments a bit more.
Need to figure out pattern tables.