prepare_to_move = function()

-- pad out one node fully, and all other nodes just enough to keep them from overlapping.
-- We don't want cascading movements to get too chaotic.
prepare_to_move = function(target)

		def.hs.x = def.w/2 + 50
		def.hs.y = def.h/2 + math.max(60, math.min(def.h/3, 200))

		def.hs.x = def.w/2
		def.hs.y = def.h/2 + 30
		if def == target then
			def.hs.x = def.hs.x + 50
			def.hs.y = def.hs.y + math.max(30, math.min(def.h/3, 200))
		end

		prepare_to_move()

		prepare_to_move(node)