Add support to manual dither either by magnitude or X,Y coordinates. Please...

Add support to manual dither either by magnitude or X,Y coordinates. Please note that if the target X,Y coordinates are far away from current reticle position, then this would cause the guider to move aggressively to the target location which might result in the star getting lost. One way to reduce this effect is by reducing the propotional gain temporary until such large moves are complete. Another method is to increase the guide square size so that large movements can still find the guide star.

BUGS:396406
FIXED-IN:2.9.7