4 - add read/write timeouts to sockets
7 - make it possible to re-open sockets
8 - add/fix socket options
11 - add MAKE-SOCKET-PAIR
12 - grovel CMSG_* macros
13 - make it possible to send descriptors/credentials over unix sockets
14 - unlink socket file when closing a passive local socket
17 - implement SCTP sockets