QualifiedNameEditor Should Propose Valid Qualified Names

The QualifiedNameEditor is used in multiple places in support of the JCR CND editor. It would be nice if the user was offered valid proposals for the unqualified name. For instance, if a namespace prefix of "nt" was selected in the QualifiedNameEditor; then valid proposals would be "base", "unstructured", "hierachyNode", "file", etc. As the user typed in more characters the number of valid proposals would get smaller. Required types and super types are two places this would be very useful.