Breakpoints stealing focus when new line added

[Kuba Ober]

> I don't think there is anything left we can do about this bug except port
> the breakpoints widget away from the QTable it currently uses. The root
> cause of this problem is a bug in QTable where it sometimes steals focus
> when elements are changed in it.

What about checking what widget has focus before updating the breakpoints, and 
restoring it afterwards?

Cheers, Kuba