first non-working cut of Chris Siebenmann <cks@utcc.utoronto.ca> rshrcmd()
kind of reworked, to fit in to the framework required for rcmd(3) to remain
as useful as it is, and for backwards compatibility.
path for /bin/rcmd.
new rcmd(1) command, mostly cloned from rsh(1).  for use with the
new rcmd(3) suite.
if #ifdef IN_RCMD, handle being rcmd(1).
handle locuser with rcmd(1).
propogate return values;  make rcmd(1) work!
use hprcmd; minor KNF.
rcmd fixes: oops: -u takes an arg; getpwuid() earlier; -u can be "me".
remove register; select -> poll
merge lite2 stuff;  fix a bit.
this program is not setuid in the new-rcmd-world-order
this program is not setuid in the new-rcmd-world-order
* set fd2p to fd of ep[] if socketpair() worked, not after failure exit.
  this should make rshrcmd() work properly now
* check if local user exists, barf if not. setuid() to them
* cleanup warnx() messages
* use memmove/memcmp instead of bcopy/bcmp
use waitpid(), as suggested by lukem.  teeny KNFing.
clean up a bit, and fix a bug in the child rcmd process.