iptables: install libext*.a into staging dir

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36867 3c298f89-4303-0410-b956-a3cf2f4a3e73
firewall: copy libext*.a from staging dir and drop kernel.mk includes, solves problem with colliding CONFIG_IPV6 symbols

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36868 3c298f89-4303-0410-b956-a3cf2f4a3e73
firewall: udpate to git head (#13652, #13654, #13658)

  - optimizes chain usage for ingress rules
  - adds limit match support for redirect rules
  - fixes automatic redirect dest detection on little endian systems
  - leaves base chains in place on reload to allow user rules to target e.g. "reject"

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36871 3c298f89-4303-0410-b956-a3cf2f4a3e73