Merge pull request #6 from jpouellet/master

use `sysctl -n foo` instead of `sysctl foo | cut -d= -f2`
xetc should be sysmerged, not extracted

(very) soon to be removed
Merge pull request #7 from jpouellet/xetc

xetc should be sysmerged, not extracted
New branch for the xetc etc removal stuff
changelog
First verify we have root privileges
We have already check for root priv as this point
Reorder to only backup if fetch / sig control / etc are successful
Add a rollback function to restore backed files and add a param to error to call it
Add rollbacks
Merge pull request #8 from jarmani/rollback

Improve process
disabling mpbios seems no longer needed, and apparently never recommended

according to http://marc.info/?l=openbsd-misc&m=141323000401751&w=2
and the next few replies.