customization of application menu

[Stephane Chauveau <s chauveau chello nl>]

Hello,

I have a system with multiple installations of gnome using a different 
prefix. For example,
I am currently installing gnome 2.1 in /opt/gnome/2.1.
The next release will go in /opt/gnome/2.2

I also have to apply the same customization to all application menus (in 
all /opt/gnome/2.x).
The files share by all releases to customize the menu should be stored 
in /opt/gnome/common.

Ideally, once the system is configured, I should be able to add or 
remove entries in the application
menu by editing some files in  /opt/gnome/common.

This is not really difficult except I could not find a way to add or 
remove a folder in the root of
application menu without editing all files 
/opt/gnome/2.x/etc/gnome-vfs-2.0/vfolders/applications-all-users.vfolder-info

Is there a way to 'include' some directories definitions into the 
application menu?

<MergeDir> could do that except that that <MergeDir> does not allow to 
select
the folder content using keywords (i.e. <query>). Also, <MergeDir> seems 
a bit
obsolete ('old style' according to 
https://listman.redhat.com/pipermail/xdg-list/2002-July/000560.html)

Stephane.