implement better caching mechanism in the context of a query.

 - multiple expressions are now properly cached, to reduce traversals.
 - it is now easier to implement a proper find.
convert attribute values (true/false) and tag names (numbers)

 - matching body > 0, [attribute=true], [attribute=null], etc.
replaceChild fix, clone, list push fix, Nodes can use Lists
fix for != operator and primitive values, value attributes

 - className and attribute with no operator use in now
defaults on Function must also accept null