Gopher: spike-clip

	There are two ways in which spikes can be clipped:
	1) Spikes don't kill you if you're moving in the direction they face,
	and gravity isn't applied when you're directly above the ground.
	If you land on the ground with an upward velocity, you can clip through
	up-facing spikes until you're eventually lifted off of the ground
	(giving a boost[1]).
	spikeclip1.gif	gif
	This clip can be done without spikes, and is useful for quickly
	restoring dashes, or getting a boost[1].
	2) In the early frames of a dash, the distance you travel in 1 frame can
	be larger than a spike's hitbox. If a spike doesn't have a solid block
	behind it, e.g., the ceiling in 2500m, you can completely dash over it.
	spikeclip2.gif	gif
	[1] Boost	gopher-menu