Warp the image in frame imf2 into the image in frame imf1, using the
control points that have been set on each.
First checks that the same number of control points has been set on both
images. Then, for each control point pair, displays a dialogue containing
a side-by-side comparison, allowing the user to adjust both positions by
dragging. Then, if the user confirms, proceeds to do the warping, mapping
the second set of control points onto the first.
Afterwards the control point positions on both images are the same and the
drawing mode is unchanged.