Added final else
Removing a package now also removes all references to it if appropriate

If there are no more pkginfos with the same name, MunkiAdmin will now also remove any references to a pkginfo.
This includes "name" and "name-version" style references from the following:
- managed_installs item in a manifest
- managed_uninstalls item in a manifest
- managed_updates item in a manifest
- optional_installs item in a manifest
- requires item in a package
- update_for item in a package