Hint update - cryptrootfs, adjust to lfs-7.1

After many headaches, I've upgraded my system to lfs-7.1, so here's the new crypt-rootfs hint in diff -aur
and as the new version.

Lars

AUTHOR: Lars Bamberger <Lars.Bamberger at gmx dot de>

DATE: 2012-05-15

LICENSE: GNU Free Documentation License Version 1.2

SYNOPSIS: How to setup an encrypted file system including the rootfs.

DESCRIPTION:
This describes one possible way of encrypting your hard drive, including the
root file system. It is intended for experienced users and tries to
circumnavigate the pitfalls of encrypting your root file system in a
straightforward way.

PREREQUISITES:
This hint requires that you have sufficient knowledge of BeyondLinuxFromScratch
and reasonably up to date software. You must be comfortable building software,
finding, reading and understanding other pertinent documentation.
You must know how to set up an initramfs. (See
'filesystems/ramfs-rootfs-initramfs.txt' in the kernel's documentation.)
You must be aware why you'd want an encrypted file system and you must
understand the nature of the threat you're trying to protect yourself against.