Python 3.3 patch for TLS-SRP support

I just posted a patch for Python 3.3 to add TLS-SRP support (Issue #11943). This patch adds support for TLS-SRP (RFC 5054) to Python ssl.SSLSocket, _ssl.c, http, and urllib. TLS-SRP lets a client and server establish a mutually authenticated SSL channel using only a username and password (a certificate may also be used to supplement authentication). Two Python-specific use cases for TLS-SRP are calling HTTP APIs that require auth, and writing test suites in Python for networked software (e.g., how Chromium uses TLSLite for network testing). More info at http://trustedhttp.org/wiki/TLS-SRP_in_Python.