Merge branch 'stable-1.4.20'

... to get 76e230e ('iptables: link against libnetfilter_conntrack'),
else static build doesn't work.

Conflicts:
	extensions/GNUmakefile.in

[ CPPFLAGS was added in master, so keep it ]

Reported-By: Gustavo Zacarias <gustavo@zacarias.com.ar>