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.