First thing:  Let's add controls!
	So far, we can't move around
	glfwSetKeyCallback (needs a window and a function)
	keystroke function (takes a window, key (as int), scancode, action, modifiers (as int)
		Constants match key, like GLFW_KEY_A and such
	Should we add a movement thread yet?
		Probably
		Constant delay for now?  Assumes CPU is really fast
		Better:  Figure out how long we actually took, and sleep accordingly

Second thing:  How about falling, or not?
	This is rather more complicated than it might seem
	Could add a fixed invisible floor, and remove it later

Lab:
	Sort of depends where we get
	I'd like to have an automatic trampoline near the origin
		But will we be far enough along?