New chapters draft: Upgrade, Backup, Recovery

Hello,

since I have encountered more than one question on the channel about how
to migrate (in other words how to backup and recovery), I have decided
to write two new chapters.

Big warning: this is just a draft and I have not tested that yet. Most
likely I will not have time until RC1 is out. If there are volunteers to
test backup/recovery on RHEL6/Debian and fill the gaps with more exact
commands, I'd be very happy.

Upgrading: https://gist.github.com/6436510
Backup: https://gist.github.com/6436535
Recovery: https://gist.github.com/6436538

Please forward your in-line comments to the PR here:

http://git.io/BgeDFQ

Thanks!

··· -- Later,

Lukas “lzap” Zapletal
irc: lzap #theforeman