Merge branch 'disable_debian_banner' into 'master'

disable the debian/ubuntu package version from being sent to clients

dkg pointed out to riseup that our ssh servers were revealing the package version to clients, which is controlled by the DebianBanner config option. It exists in both Debian and Ubuntu and defaults to 'yes', so we explicitly set it to 'no' in the templates for those distros.

See merge request !17

diff --cc templates/sshd_config/Debian_squeeze.erb
Simple merge

diff --cc templates/sshd_config/Debian_wheezy.erb
Simple merge