'Remove a handler type for a JID and node combination.
The next handler in the hierarchy will be used if one
exists. If removing the global handler, make sure that
other handlers exist to process existing nodes.
Node handler hierarchy:
JID   | Node  | Level
None  | None  | Global
Given | None  | All nodes for the JID
None  | Given | Node on self.xmpp.boundjid
Given | Given | A single node
Arguments:
htype -- The type of handler to remove.
jid   -- The JID from which to remove the handler.
node  -- The node from which to remove the handler.'

def del_node_handler(self, htype, jid, node):

    self.api.unregister(htype, jid, node)
