initial commit of upstream Gentoo initscript

contrib/Gentoo/rc.firewall from commit
6dc9fb8aa1bbf47aafdb5d4ddfa5d83c347e7acf
remove stats command

- the status function cannot be used fully without runscript supporting
  additional command line arguments
replace help command with proper description
add command and description
replace LOCATION with command
remove ebegin/eend messages

- arno-iptables-firewall script itself writes out plenty of information
  about the requested operation
fix reload command
remove old initscript patch
install new initscript
drop the now unused patch/eutils
don't install the now unnecessary conf.d file
add conditional dependency on net-dns/bind-tools

Some plugins require dig or nslookup to be available.
move sed into src_prepare
fix documentation path by installing the files earlier
remove unnecessary empty lines
update Manifest