Changing allow_reuse_address's default value, and documenting it.

Doc/lib/libsocksvr.tex

@@ -94,6 +94,11 @@ The socket object on which the server will listen for incoming requests.
 
 The server classes support the following class variables:
 
+\begin{datadesc}{allow_reuse_address}
+Whether the server will allow the reuse of an address. This defaults
+to true, and can be set in subclasses to change the policy.
+\end{datadesc}
+
 \begin{datadesc}{request_queue_size}
 The size of the request queue.  If it takes a long time to process a
 single request, any requests that arrive while the server is busy are

Lib/SocketServer.py

@@ -157,7 +157,7 @@ class TCPServer:
 
     request_queue_size = 5
 
-    allow_reuse_address = 0
+    allow_reuse_address = 1
 
     def __init__(self, server_address, RequestHandlerClass):
         """Constructor.  May be extended, do not override."""