Metadata module

[nikmd23]

A not-yet-complete list of requirements for the metadata system:

• Serve metadata from a resource (#23)
• Tell clients which filtering mechanisms are available
• Tell clients about URI templates to various resources
• Provide cache busting hash
• Provide list of SPA Client extension URLs?
• Any agent specific metadata?

This is a list of requirements, not tasks. As such, this list is not work to be completed, but rather things to be considered when designing the metadata module.

[nikmd23]

@avanderhoorn, this is getting close. Might be time for you to take a look at it too.