Support metadata consisting of arrays of any of the simple types.

Also, overhaul oslquery/oslinfo metadata parsing, it was quite brittle and broken for aggregate types such as colors.

This patch overhauls oslquery's parsing of metadata.  Aggregate types (points, colors, etc.) are fine now for metadata, and also you can have metadata that is an array of a basic type. Still no structs or closures, or metadata itself having metadata.