[gentoo-hardened] RFC doc on hardened.

[klondike]

Well as some of you may remember by June I wrote a document on why
using gentoo hardened is a good idea explaining some common attacks and
what were the grsecurity, PAX and hardened features to avoid them.

I have reread the doc and expanded some parts as work previous to
formatting it as GuideXML and publishing it on the hardened site
(probably split in various docs).

Again I'd like to know your opinions on what should be fixed (if
anything should).

If there is no major complaint, these texts will be the ones used on the
GuideXML docs (+ some examples that I'll try to write).

klondike