Added ability to parse a SDPSession object from a string

Ignore-this: 1e1a655a3a4c4fe86b4d9a6e08e74d48

darcs-hash:20130218172051-56b4d-3ef51571f311d75fca714743cf7f80e68c25a62c
Disable PJSIP assertions on recoverable errors

Ignore-this: 6ed15b9c0a44269f04b89344384d02dd

darcs-hash:20130219115501-56b4d-85139f84b3b483204c66509908278e28d282f27d