Comment 4 for bug 990623

Looking at the code, I found that this border change is, or better should be a hover effect. The Problem was that the statebox class needed to handle mousemove to use the handle_mousein method.
I fixed this in rev 6378.
The hover rectangle should be outside of the checkbox border on all sides, but in the right, it lays on top of it and I couldn't make it more width. (say: the hover highlight can't be a square bigger than the checkbox and is a rectangle instead.) I don't know why.
So look at it and decide if this bug is fixed or the mouse-over pics should be implemented...