docker: ensure socat is installed

install_docker.sh failed for me because socat wasn't installed.  Add it
to this script since it expects it to be there.

Change-Id: Ic55f5e38de1b38bdd37407b7bec533d4c3eff2a9
xenapi: Use C locale

By exporting the LC_ALL=C we can get rid of localisation issues, as the
actual scripts are already assuming an english installation.

FIxes bug 1227527

Change-Id: Ieeebce4d53b09959146a970f3fb803201ac5ebdf
Merge "xenapi: Use C locale"
Merge "docker: ensure socat is installed"