[TxMt] Submenus in bundles and the info.plist

[Mark Sprevak]

I'm writing a bundle and I would like to add create some submenus.

I understand that the association, and ordering, of commands in bundle menus
is achieved via the `info.plist` property list for the bundle. New commands
are generated with an ID number that can be referenced in the `info.plist`.

Submenus also have ID numbers that appear in the bundle's `info.plist`.
However, these submenu ID numbers don't appear to be generated, or to
feature, elsewhere in the bundle.

My question is: how does one create the ID numbers for submenus in
`info.plist`? Would any random ID that is distinct from the others in the
`info.plist` do? What about collisions with numbers in other bundles? How do
folks usually generate these submenu ID numbers?

Final question: is there any faster way to manage menu structure of a bundle
other than fiddling by hand with `info.plist`?