Add circle rasterization; mod README, screen.

Add:
	README.md
		-add ncurses hyperlink to list of dependencies.

	src/graphics.c
		-add drawCircle(), which rasterizes a circle by adding edges to a point
		matrix -- the algorithm is slow, but the more efficient versions aren't
		particularly compatible with our use of a master point matrix. Avoiding
		premature optimization.

	src/interpreter/interpreter.c
		-add command to draw a circle.

Mod:
	src/screen.c
		-drawPixel() now plots pixels at an offset of
		(IMAGE_WIDTH / 2, IMAGE_HEIGHT / 2), to center everything on the origin.
Clean engine.c, add drawCircle() macro.

Add:
	src/engine.c
		-remove textMatrix() and testRasterizeLine(), as the functions were used
		simply to test functionality and are no longer necessary.

	src/graphics.(c, h)
		-replace drawPolygon() body with the more efficient algorithm used by
		drawCircle() (which essentially renders a polygon with a large number of
		sides); replace drawCircle() with a macro that calls drawPolygon() with
		a number of sides equal to its radius, which is large enough to create
		the illusion of perfect circularity.
Add functional Bezier curves.

Add:
	src/graphics.c
		-add drawBezier(), which renders a Bezier curve.
Add functional Hermite curves, curves script.

Add:
	src/graphics.(c, h)
		-add drawHermite(), which draws a Hermite curve.

	scripts/curves.gsc
		-add script to generate a face, using circles, Hermite, and Bezier
		splines.

	src/interpreter/interpreter.c
		-add commands to draw Bezier and Hermite curves.

	src/interpreter/file_parser.c
		-add 10 second usleep before evaluateScript() quits the screen, to allow
		some time for the user to observe the screen.