nowrap on date in mailbox

[Michael Bull]

... I just added a 'nowrap' to the date in the message_summaries.inc file, 
and I like the look much better; often it was just the date that was being 
wrapped onto the two lines, and there is more than enough text to break 
onto two lines between the sender and subject that I think it's better to 
keep the date field intact.   Would this be something that can be added to 
the cvs?  It really does make things look cleaner at 
resolutions/window-sizes where the date would be wrapping.