- Removed the exception parameter from the initialize callback and, by extension,
        JSObjectMake. We have never had a need for exceptions when iniitializing,
        so the parameter seemed likely to "get in the way." 
        
        Also, an exception in JavaScript is thrown in response to input -- 
        "invalid URL", "index not a number", etc., so it's the job of the 
        constructor function, not the initialize method, to throw.
        
        If initialize *really* wants to throw, it can communicate the throw to
        the constructor through the constructed object's private data (e.g., set
        it to NULL, signaling to the consntructor that initialization failed.)
        
        - Added JSObjectMakeWithData, which enables a constructor to set private
        data on an object *before* it has been initialized. That way, the initialize
        methods can properly operate on the data. 

        * API/JSNode.c: Moved ref into the initialize method, for better encapsulation,
        now that it's possible.
        * API/JSNodeList.c: ditto
        * API/minidom.c:
        (main): Do more aggressive garbage collection to test ref/deref and 
        initialize/finalize.
        * API/minidom.js: store childNodes in a temporary so it doesn't get re-created
        like a thousand times. This makes debugging ref/deref easier



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@15484 268f45cc-cd09-0410-ab3c-d52691b4dbfc