olpc-update for 12.1.0

[Daniel Drake]

Should now be working:
http://wiki.laptop.org/go/12.1.0#Online_upgrade

>From Terminal activity, e.g. for build 8:
sudo olpc-update 12.1.0d_xo1.75-8
sudo olpc-update 12.1.0d_xo1.5-8
sudo olpc-update 12.1.0d_xo1-8

Note that pristine upgrade won't work yet (to be fixed in next build).

Daniel