Added python-msrplib dependency in install documentation and debian package

darcs-hash:20081219114524-58252-0a578993f9f1b6ab3766bda20be7e2f071f29893
Added "transport" parameter to "sip_trace" event

darcs-hash:20081219170543-58103-22329a65f18bca76f4ab636ed413e8370027894c