io_set_close_on_exec, to avoid fd:s leaking to user shells.
* src/werror.c (werror_argp_parser): Likewise.
* src/server_pty.c (pty_open_master): Likewise.
* src/unix_interact.c (make_unix_interact): Likewise (even if this
is in the client).
* src/io.c (lsh_pushd_fd): Likewise.
(lsh_pushd): Likewise. Also fixed EINTR logic.

Rev: src/unix_interact.c:1.29
Rev: src/werror.c:1.74