- The quicklinks.exsd defines two attributes that are specified as
IDREFs to command IDs but they actually permit a command spec and even
wildcards.
- This leads to warnings when those aspects are used and those warnings
are impossible for the user to fix.
- If we disable the basedOn type for those, the extension attributes no
longer support Browse... to find a command, which makes authoring very
inconvenient.
- Ideally PDE is made aware of these special attribute so support
specialized validation.