How to add menu entry to Tools-menu - working with both official 21.3 release and current CVS-Emass

[klaus.berndl]

AFAIK easy-menu.el has been changed with respect to some internals,
so some people have reported that some menu-related code of some
packages doesn't work anymore.

Therefore my question:

The ECB-package wants to add a menu-entry "Start Code Browser (ECB)"
bound to the command `ecb-activate'...

What is now the recommended code to add a new menu entry to the "Tools"-menu
when it should work with the current official release 21.3 and also with
the forthcoming 21.4 release (the current CVS-version)?

Thanks for your help,
Klaus