Add test.test_support.transient_internet . Returns a context manager that

nests test.test_support.TransientResource context managers that capture
exceptions raised when the Internet connection is flaky.

Initially using in test_socket_ssl but should probably be expanded to cover any
test that should not raise the captured exceptions if the Internet connection
works.

Lib/test/test_socket_ssl.py

@@ -27,7 +27,7 @@ def test_basic():
         print "didn't raise TypeError"
     socket.RAND_add("this is a random string", 75.0)
 
-    with test_support.TransientResource(IOError, errno=errno.ETIMEDOUT):
+    with test_support.transient_internet():
         f = urllib.urlopen('https://sf.net')
     buf = f.read()
     f.close()