Add globals.h (ERROR macro), parser.(c, h).

Add:
	src/globals.h
		-add globals.h file to contain macros universally applicable to the
		graphics engine
		-add ERROR() macro, used to print either a plain string, or formatted
		string, error message with filename and line-number metadata.

	src/parser.(c, h)
		-add files that will form the backbone of the graphics engine's
		parsing utility.
		-add readScriptFile(), freeScript(), Script_t struct.
Fin script parsing; add scripts/; mod matrix.*

Add:
	src/parser.c
		-complete, and test script-file parsing
		-add evaluateScript(), evaluateCommand(), and argsRequired();
		evaluateCommand() should map nicely onto an interactive shell
		implementation.

	src/parser.h
		-add Script_t definition, though that'll likely move back to
		parser.c.

	src/matrix.c
		-remove static specifier from createIdentity(), as the function's now
		called by parser.c and isn't matric.c-specific.

	src/matrix.h
		-add Matrix_t definition, though, as with the Script_t definition in
		parser.h, that's also likely to change once all testing finishes.

	scripts/
		-add directory to contain all script files.
Add screen-saving, rm engine.h, add to gitignore.

Add:
	src/screen.c
		-add writeScreen(), which writes the current SDL_Surface to a file.

	src/parser.c
		-add documentation comments before every function header
		-add ability to save current SDL screen to file from a script.

	src/(engine, globals).h
		-move the only declarations in engine.h, MAP_HEIGHT and MAP_WIDTH
		macros, to the globals header, and remove engine.h (engine.h was being
		used as a globals file, which is better conveyed by a file called
		globals.h).

	.gitignore
		-add *.bmp files