Add MSG_EOF and MSG_EOR suppor for sendmsg() on FreeBSD.
Add MSG_EOF and MSG_EOR suppor for sendmsg() on FreeBSD.

This does not affect the userland stack.

weinrank/usrsctp,sctplab/usrsctp,CoolmanCZ/usrsctp,CoolmanCZ/usrsctp,CoolmanCZ/usrsctp,weinrank/usrsctp,weinrank/usrsctp,sctplab/usrsctp,CoolmanCZ/usrsctp,sctplab/usrsctp