Set adminstrative domain for the process when looking up user's
password or group info and when preparing for execve().
Include strings.h even if string.h exists since they may define
different things. Fixes warnings on AIX and others.
not a tty. Instead, check whether stdin is a tty and if not, delay
setting the tty to raw mode until the command tries to access it itself
(and receives SIGTTIN or SIGTTOU).
an -I flag is specified. The files in the compat dir could get away
with double quotes here but I've converted all the source files
to use angle brackets for consistency.
