[Cuis] Using packages saved in current versions with older versions of Cuis

[Phil (list)]

One thing I'm running into as I'm going back and forth between Cuis
versions to migrate my code is that the new package versioning /
dependency metadata appears to result in 4.1 and earlier having problems
loading packages saved by the newer version.  Not a big deal, but it
might be worth considering making the package loading code a bit more
tolerant by having an option to ignore (perhaps with a warning or
transcript logging) metadata it doesn't understand.