Validation meta-Properties should only show up if they are relevant, and then should be front-and-center

Summary: We're beginning to add new Properties such as Maximum Number Value, which are relevant only when applied to a Property of a particular Type or Types. Currently, those are buried in the long list of miscellaneous Properties you could add to something. But they should be context-sensitive. If the Property isn't the right Type, they should be hidden. If it is the right Type, they should be easier to find.

This may be driving towards more flexibility in the design of the Property Editor.