NAME
	MoveLayer -- Move layer to new position in BitMap.

    SYNOPSIS
	result = MoveLayer( dummy, l, dx, dy )
	d0                  a0     a1 d0  d1

	LONG MoveLayer( LONG, struct Layer *, LONG, LONG);

    FUNCTION
	Move this layer to new position in shared BitMap.
	If any refresh layers become revealed, collect damage and
	set REFRESH bit in layer Flags.

    INPUTS
	dummy - unused
	l - pointer to a nonbackdrop layer
	dx - delta to add to current x position
	dy - delta to add to current y position

    RETURNS
	result - TRUE if operation successful
	         FALSE if failed (out of memory)

    BUGS
	May not handle (dx,dy) which attempts to move the layer outside the
	layer's RastPort->BitMap bounds .

    SEE ALSO
	graphics/layers.h, graphics/clip.h