Added tls_credentials property to account objects

Ignore-this: 87fa30102b41f5973fc962b58de1810f

darcs-hash:20091014151346-1e3d8-721c527c3ded9b96443f0d8e189d6625d8b0af7e
Added copyright notice to msrpstream.py

Ignore-this: aa8c7e4806babea755bc5b8a0c4e9fbc

darcs-hash:20091012233907-b22ec-ddc7c7b09b1874ce708ac79ccc7eaf95d11fc4cf