gEDA-user: [pcb] gtk crosshair enter/leave patch

[DJ Delorie]

> GTK Suggestion: When you're depositing components, you get a
> wire-frame component.  That's fine, but when you leave the canvas, the
> wire-frame should disappear.  As it's currently implemented, the
> wire-frame is still drawn.  If you go to the library and select a
> different component to deposit, the current wire-frame remains
> visible.  It's obviously being drawn using XOR and somebody forgot to
> do an extra XOR on exit.

I fixed this one.  Hopefully there won't be any odd interactions
between this patch and some obscure gtk-isms.