Add aws-ubuntu-12-04 image list to live-test

Uses us-east-1/ami-3c994355
Log action context at info
Log return-value-expr at debug
Add hosts-for-role and sanitise localhost

When the hostname is not in the list of ips provided for /etc/hosts, add it as a
psuedonym for localhost (prevents sudo from complaining).
Log live-test failures at debug
Update to ssh-transport 0.1.2