planegane, fix audio play of number above 9

Number 10 was played as 1.
redraw, add an animation on the selected color
sudoku, add an animation on the selected color

Made the circle ovale so that the rotation animation is visible
redraw, replace the white color icon by an eraser

The image comes from the tango icons from openclipart.
mosaic, better implementation of the selector

There was a corner case where the zoom on the selected item could be lost.