Go back to resetting the refresh counter after a DMA. Probably not quite correct as it is probably reset on VDP triggered refresh, but this is close enough for now given the general limitations with my refresh code. VDP FIFO Testing seems to be passing 100% reliably again (was occassionally failing still with the last commit)

    dc.l $0, start
start:
	moveq #36, d0
	bsr fib
	illegal
fib:
	cmp.l #2, d0
	blt base
	subq.l #1, d0
	move.l d0, -(a7)
	bsr fib
	move.l (a7), d1
	exg d0, d1
	move.l d1, (a7)
	subq.l #1, d0
	bsr fib
	move.l (a7)+, d1
	add.l d1, d0
	rts
base:
	moveq #1, d0
	rts