String change in libgnomeui

[Kjartan Maraas <kmaraas broadpark no>]

Hi.

I commited a change to mark a couple of strings for translation in the
crash dialog from libgnomeui. Took the oportunity to add mnemonics to
the three strings there also, so we have a total of three strings that
need updating in that module.

Hope this is ok with everyone and if not please voice your opinion here.

I'm going to go hunting for strings that aren't marked for translation
tonight, but I hope there are very few left...

Cheers
Kjartan