domxml: getting a node's XML (using xmlDumpNode)

Sure, documents can call dumpmem(), but there's no way to get the XML of a node. Until now! Not knowing at all what I was doing, I copied code from the function unlink_node and modified it to call xmlDumpNode(). It works for me, though I expect there's probably a memory leak in it since I don't know (right now) the proper way to deallocate an xmlBufferPtr. To make it work, you need to edit php_domxml.c and insert a suitably modified line everywhere you see a reference to unlink_node. -- .tom