Auto Away should change busy state and restore it

[sander]

When presence is set to busy (do not distrurb) and the auto-away feature is enabled, the busy presence state should also change to away and extended away after the specified time intervals. When activity is detected on the computer, the previous busy state should be restored and not be set to available like it is now (this is a bug!).

An even better fix for this bug would look like this:
1) when auto away changed busy into away and activity is detected: just set back to busy (it is very likely that the user is still busy and he simply when to bathroom e.g.)
2) when auto awaychanged busy into extended away and activity is detected: show a popup dialog where the user has to choose if his presence state should be changed to busy again or to available (the chances are higher that the user may not be busy any more)