Merge pull request #40 from andrew-d/andrew-support-sslv2

Allow creating a Context with SSLv2_METHOD, a feature which was accidentally dropped in the Python port.
diff --git a/OpenSSL/SSL.py b/OpenSSL/SSL.py
index a257f16..67e4c82 100644
--- a/OpenSSL/SSL.py
+++ b/OpenSSL/SSL.py
@@ -235,6 +235,7 @@
     new SSL connections.
     """
     _methods = {
+        SSLv2_METHOD: "SSLv2_method",
         SSLv3_METHOD: "SSLv3_method",
         SSLv23_METHOD: "SSLv23_method",
         TLSv1_METHOD: "TLSv1_method",