Refactor Gentoo Menu, found that minimal ISOs don't work well with iPXE

Extracted out ISOs using method found here at: http://blog.dastrup.com/?p=12
Have injected the squashfs into the initrd and now am hosting the latest minimal ISO
on boot.rackspace.com.  Added warning notes on the menu.  This should at least
get Gentoo booting so that an install can be done as opposed to not working at all.