This system is experimental, and replaces/updates the old content system (which was really part of 0.2 or 0.3).
- is a record in the node table
- can have zero or more 'leafs
- There's generally no point to having zero, but no reason to forbid it.
- can have a (node) type which points to a handler-class
- so that when we're looking at a group of unspecified nodes, we know how to handle each one
- a data type
- a name (unique within the node)
- a value
- is like a single field in a single record