4.4BSD snapshot (revision 8.1); add 1993 to copyright

trailing comment after #else or #endif

get rid of obsolete structures and allow timer-setting routines to be macros

adopt TCP's policies concerning acks & (among others) use the fast
timeout mechanism and delayed acks.

effectively merge tp_ref structure with rest of tp_pcb;
this version doesn't crash, but does exhibit lumpy behavior;
ack & retrans policies need to be fixed

new copyright; att/bsd/shared

checkpoint for ``alpha tape''; tp is still a little broken.

Checkpoint as of first successful tp connection, before posix, &
before mckusick starts incorporating gnodes

date and time created 88/12/14 15:30:18 by sklower