Adding hierarchy and authorization

[joepio]

Atomic Data needs a bit of Hierarchy.

• Add new class (Drive) and properties (parent, edit, read)
• When initializing a Store, add a Drive and give edit and read rights to the new Agent.
• Put populate data (collections) as children in drive
• Add parent / require parents with Commits (require a Parent as a property to be present in a Resource or its commit, or default to some uncategorized parent, check)
• Check (parent) read rights before returning resource
• Check (parent) read rights in collections
• Check (parent) read rights in websocket connections Websockets for Commits / subscribing #171
• Check (parent) edit rights before applying commit
• Check circular references before applying commit #218
• Add structure to default store (maybe organize in an ontology?) #219
• Add structure to default Collections (probably add to default Drive)

[joepio]

How to implement the rights check feature? For any given resource, I'd like a fast and clean implementation of checking whether a specific Agent has write or read access to the resource. How to do this? Where to add this?

• Since it will recursively check for parent properties, how do we prevent loops?

check_rights(agent, store) -> read: bool, write: bool function on Resource

• Might save a single DB request, because we already have one resource

check_rights(subject, agent) -> read: bool, write: bool function on store

[joepio]

Checking the children of a resource requires performing a TPF query, which means it could get real expensive with the current implementation. Will soon have to work on indexes / caching #14