Major overhaul of timeout sockets:

- setblocking(0) and settimeout(0) are now equivalent, and ditto for
  setblocking(1) and settimeout(None).

- Don't raise an exception from internal_select(); let the final call
  report the error (this means you will get an EAGAIN error instead of
  an ETIMEDOUT error -- I don't care).

- Move the select to inside the Py_{BEGIN,END}_ALLOW_THREADS brackets,
  so other theads can run (this was a bug in the original code).

- Redid the retry logic in connect() and connect_ex() to avoid masking
  errors.  This probably doesn't work for Windows yet; I'll fix that
  next.  It may also fail on other platforms, depending on what
  retrying a connect does; I need help with this.

- Get rid of the retry logic in accept().  I don't think it was needed
  at all.  But I may be wrong.

Lib/test/test_socket.py

@@ -51,7 +51,10 @@ class ThreadableTest:
         self.queue = Queue.Queue(1)
 
         # Do some munging to start the client test.
-        test_method = getattr(self, '_' + self._TestCase__testMethodName)
+        methodname = self.id()
+        i = methodname.rfind('.')
+        methodname = methodname[i+1:]
+        test_method = getattr(self, '_' + methodname)
         self.client_thread = thread.start_new_thread(
             self.clientRun, (test_method,))