Don't enable "Save As" if you don't have an unsaved live capture file

Don't enable "Save As" if you don't have an unsaved live capture file
and there are no formats in which the file can be saved by some means
other than copying the raw data; "Save As" isn't a very useful function
in that case, and that prevents us from having an empty list of formats
in which the file can be saved.

svn path=/trunk/; revision=21032