gnome-app-helper and tearoff menus

[Federico Mena Quintero <federico nuclecu unam mx>]

Hello, guys

Gnome-app-helper's gnome_app_fill_menu_custom() is unconditionally
adding a tearoff menu item to subtrees.  Even though it uses
gnome-preferences to see if it should do it, this is not relevant for
the problem I am having.

GMC creates some popup menus on the fly, and these may have subtrees.
It is bad to make the subtrees have tearoff items in them.  As far as
I can tell there is no way to tell gnome-app-helper not to put in the
tearoff item.

For GMC we'll have a hack that destroys the tearoff item after the
menu is created, but this is Ugly(tm).

We cannot change the API at this point, however.  It is just a point
to keep in mind.  The functions that create menus should take in an
additional argument that says whether to use tearoff subtrees or not.

  Federico