DOMIT! version 0.52 released

DOMIT! version 0.52 has been released. This fixes a bug in the DOMIT_NodeList class, in which appendNode and removeNode were returning a shallow copy of DOMIT_Node.

A new DOMIT! tutorial has been added: "OOP Techniques for Modifying an XML Document: Part 1".

Some minor revisions to the old DOMIT! Tutorial have been made.