[pyOpenSSL] Patch to x509ext.c to add getter for extension short name

[Alex S. <ale...@pr...>]

http://prol.etari.at/pyopenssl/X509Extension_get_type_name.patch

This patch adds a method to the X509Extension class to return the
short name (e.g. basicConstraints) of the extension.

-- 
Alex Stapleton