RFC: make menu implementations tolerant of vendor changes

[Bill Nottingham]

In Fedora, we've had the issue where some desktop files were incorrectly
shipped with a vendor prefix. Due to the fact that the file name often
is used as a key, we then are 'stuck' with either maintaining the bad
vendor prefix indefinitely (potentially incompatibly with other distributors
or upstreams), or changing the vendor prefix (breaking edited menus, user
shortcuts, and so on.).

One solution would be to have implementations be tolerant of vendor changes
in desktop file names - if they don't find a file with the vendor prefix, to
try again without the vendor prefix. Is this something that's worth adding
as a recommendation for implementations via XDG, or are there better
solutions?

Bill