Halt channel in ticks milliseconds and return the number of channels set to expire

If channel == -1, halt all channels.

Property definitions

sdl2 $ Mix :: expire_channel
	# Halt `channel` in `ticks` milliseconds and return the number of channels set to expire
	#
	# If `channel == -1`, halt all channels.
	fun expire_channel(channel, ticks: Int): Int `{
		return Mix_ExpireChannel(channel, ticks);
	`}
lib/sdl2/mixer.nit:119,2--124,3