[SCTP]: Allow linger to abort 1-N style sockets.

Enable SO_LINGER functionality for 1-N style sockets. The socket API
draft will be clarfied to allow for this functionality. The linger
settings will apply to all associations on a given socket.

Signed-off-by: Vladislav Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>