Rename qn->node, and begin implementing properties, refs #2.
Invert the way children are joined to the query, let
the child do it.
Slowly getting there on properties.
Querying of properties is working, but could be a lot nicer.
Limit child queries to the entities returned on their parent level.
Fix bugs with properties queries and clean up, fixes #2.
Cleanup and pagination, fixes #3.