of global utent/utxent variables. Only reuse the ut_id and maybe
the ut_host fields from utmp.
* lib/prototypes.h, libmisc/utmp.c: Removed checkutmp(),
setutmp(), setutmpx().
* lib/prototypes.h, libmisc/utmp.c: Added get_current_utmp(),
prepare_utmp(), prepare_utmpx(), setutmp(), setutmpx().
* libmisc/utmp.c (is_my_tty): Only compare the name of the utmp
line with ttyname(). (No stat of the two terminals to compare the
devices).
* libmisc/utmp.c: Use getaddrinfo() to get the address of the
host.
* configure.in: Check for getaddrinfo().
* configure.in: Use AC_CHECK_MEMBERS to check for the existence of
fields in the utmp/utmpx structures.
* configure.in: Reject systems with utmpx support but no ut_id
field in utmp. This could be fixed later if needed.
* src/login.c: Use the new utmp functions. This also simplifies
the failtmp() handling.
* src/login.c: passwd_free() renamed to pw_free() and
shadow_free() renamed to spw_free()