Replacing Class by Item

Class creation/instantiation mecanics like:

var A = function(){};
A.prototype.foo = 'bar';
var a = new A();

becomes:

var A = {foo: 'bar'};
var a = Object.create(A);

Object.append/merge,/clone use 'ownPair' as before
Item.implement is the only iterating on 'eachPair' (and goes up the
prototype chain to act on every pair)

Item.define(name, object, properties...)
-> store an object under name, add the __name__ property, merge with
properties
Item.extend(object,, name, properties...);
-> create an subobject linked by prototype to object then call
Item.define
Item.create(name, properties...);
-> a shortmethod equivalent to Item.extend(Object.prototype, name, ...)