Add function scanline algorithm.

Add:
	src/graphics/graphics.c
		-Add `scanlineRender()`, a functional implementation of the scanline
		algorithm.

	src/graphics/matrix.c
		-Update `drawMatrix()` to call `scanlineRender()`.
Add overloaded drawLine() with color.

Add:
	src/graphics/graphics.(c, h)
		-Add an overloaded `drawLine()` macro (built on some helper macro
		hacks), which accepts an optional color value.
Fix scanline rendering bugs.

Add:
	src/graphics/graphics.c
		-Fix bugs in `scanlineRender()`, which caused either quasi-infinite
		loops (which presumably terminated only after double overflow) or
		resulted in the lowest vertex of a triangle being identified as the
		highest.

	src/graphics/matrix.c
		-Add additional triangle for every triangle currently added, because the
		sphere was only half-filled.
Fix sphere creation.

Add:
	src/graphics/matrix.c
		-Temporarily add different colors to `drawMatrix()`, for testing
		purposes.