Updated rangeTree class with the following:
	removeRange() is now freeRange() and returns an error code if it
		fails
	addRange returns an error code if it fails
	rangeTree struct now has uintptr_t's instead of ints
	isFreed() has been added
	Class should now be able to remove nodes when freed and
		space is covered by other nodes.
	TODO: change length value to size_t
	      Correct commenting and style