New string in Yelp

[Don Scorgie <Don Scorgie org>]

Hi,

I've just committed a fix to yelp which adds a new string:
    	container->default_snippet = g_strdup (_("No Comment"));

This stops badness when the default comment for a document is NULL.

For reference, the original bug is at:
http://bugzilla.gnome.org/show_bug.cgi?id=501559

Thanks
Don