Removed unused settings

darcs-hash:20081103185852-58252-8edebc593b0c792d729c9d88dfb635956a0b8dbd
Made intermediate SDP manipulation classes more flexible in preparation for new Invitation architecture

darcs-hash:20081104163334-58103-e42c426967fc6a34a91df9b7fec79facf43dd95a