Code review comment for lp:~mikefletcher/mago/gnome-screenshot

I think the exception handling is a bit much. However it is consistent with
the rest of the code and i'm not interested in rocking.

The ldtp exception says
    u'Unable to find object name in application map'

And the exceptions we raise says
    'Window dlgSaveScreenshot did not appear'

I think a good solution would be to add information to the ldtp exceptions
so that the mago exception handling is superfluous. But I wont mention it
again until I have written a patch :).