sasl.h, m_sasl.cpp: Add RemoveSession(), DeleteSessions(), and have active sessions closed when a Mechanism is unloaded
Anope::string: Add .data()
base64.cpp: B64Decode(): Don't crash on "="
sasl.h, m_sasl.cpp: Move IdentifyRequest to the header
m_sasl_dh-aes: Add module
m_sasl_dh-blowfish: Add module
modules.example.conf: Add info about m_sasl_dh-aes and m_sasl_dh-blowfish
Merge pull request #48 from ShutterQuick/2.0+nnghsasl

Add SASL mechanisms DH-AES and DH-BLOWFISH