Add basic SCTP packet logging.
Add basic SCTP packet logging.

Attempts to get wireshark to decode the DTLS were problematic (wireshark only does it for certain versions of some DTLS implementations), so just do what firefox does and dump a txt2pcap-compatible log when requested.

R=pthatcher@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/49159004

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#9162}

TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc