On incoming session, only consider streams with a port that is not 0 as proposed

darcs-hash:20090203145322-58103-dd30609492817b23a1c67b726c9832db068b925c
Removed SCSessionIsIncoming notification in favour o SCSessionChangedState

darcs-hash:20090203161809-58103-08ebe09d8444b1e3cf7d1572201ee7ec94ab6c7c