chiral.net.tcp: change TCPConnection.connection_handler() to raise No…

…tImplementedError within a generator

function. As a result, one may create and manipulate a bare TCPConnection as long as it is never actually
start()ed. 



git-svn-id: http://chiral.j4cbo.com/svn/trunk@87 a827fe29-2235-0410-a7a9-cacdfe24a5d3

chiral/net/tcp.py

@@ -49,6 +49,7 @@ def connection_handler(self):
 		is initialized. It should be overridden in the derived class.
 		"""
 		raise NotImplementedError
+		yield
 
 	def connection_handler_completed(self, value, exception):
 		"""