update the scripts to work with the latest msrplib

darcs-hash:20090220140158-b2873-7408f56187ed5f3872e18d7d19ef082d3ebc3e81
Added call_id property to Invitation object

darcs-hash:20090220145847-58103-eefdc8659ace6cc9f3b0adbba59e5d484411bec8