Applying updated patch from Issue 1736190, which addresses partial

issues in: 909005 and 17361001, as well as completely as possible issues
539444, 760475, 777588, 889153, 953599, 1025525, 1063924, and 658749.
This patch also includes doc and test updates as necessary.

Lib/test/test_asyncore.py

@@ -27,6 +27,9 @@ class dummychannel:
     def __init__(self):
         self.socket = dummysocket()
 
+    def close(self):
+        self.socket.close()
+
 class exitingdummy:
     def __init__(self):
         pass