bust this file up into several. Its *way* too big to deal with.

   create common funcs for repeated "types" of parsers.  i.e. a common
   func for handling guid, gnc_numeric, etc. parsers - just pass in
   string->data and data->string funcs.

   change sixtp_child_result to sixtp_result?

   add generic accumulate chars node constructor - takes end_handler
   as argument - same as for timespec parser...

   document that right now parsing is *extremely* anal - no whitespace
   surrounding data.

   need to add a way to propagate error data upward...

   do we need a way to pass an object up through the tree along with
   its lower level destructor?

   CHECK TO SEE IF WE ALWAYS DTRT IN THE END TAG HANDLER - IE DO WE
   CLEANUP PROPERLY SINCE AT THAT POINT THE FRAME CLEANUP HANDLER WILL
   **NOT** BE CALLED.

   CHECK TO SEE THAT WE'RE SETTING SHOULD CLEANUP TO FALSE EVERYWHERE
   WE SHOULD (i.e. when we use the result)!

   DAMN, why didn't I think of this before.  I should have added a
   parent "after-child" hook.  I think that might have greatly
   simplified some of the nodes...

   Do we also want "before/after" chars handlers?