[Denemo-devel] Another showstopper fixed.

[Richard Shann]

If you open a new score and (using the menus) add 4 more (default)
staffs then click on New you get a crash.
I have fixed this; the fix is not so clear cut as previous ones. Please
look out for possible failures to update the display on deleting staffs.

I found the bug while trying to look for the (more minor) one reported
by Clif. It is noticeable how threatening to release finally gets people
to report bugs! We have had more Denemo crashes removed in the past
couple of days than in the previous couple of months...

Richard