Recognize AIX, define TARGET_AIX

Recognize AIX, define TARGET_AIX

force "have_tap_header=yes", as configure won't like AIX headers otherwise
(no tun related headers, just <net/if_tap.h>).

force ROUTE to be "/usr/sbin/route" - not executable by non-root users, so
configure testing for executables will not find it

force "ac_cv_header_net_if_h=no", because AIX' <net/if.h> pulls in AIX'
<net/route.h>, which #defines ROUTE_H, disabling our "route.h"... (and
we don't need <net/if.h> on AIX anyway)

Signed-off-by: Gert Doering <gd@medat.de>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <1402409073-54067216-2-git-send-email-gert@greenie.muc.de>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8787
Signed-off-by: Gert Doering <gert@greenie.muc.de>