Adding kernel config based off http://dev.gentoo.org/~rich0/kconfig-xen.txt for EC2 base and http://www.gentoo.org/proj/en/hardened/pax-quickstart.xml for PaX options. Main modifications are netfilter options here and there, disabling USB (virtual client after all) and sound card, and finally enabling ext4 by default as the root fs is formatted that way
Don't really need squashfs stuff. Point to the new kernel config.