normalized return codes in bin
refactored galaxy classes a bit, ignoring 'compatct' role spec

added AnsibleOptionsError
removed pulicate parser error class

All v2+ callbacks can now optionally define a CALLBACK_TYPE, which
when set to 'stdout' will limit those callbacks which are used for
primary output to a single callback plugin (specified to the
TaskQueueManager object and configurable in ansible.cfg/environment)

accidentally 'fixes' ubuntu distribution parsing, this order should not matter, need followup to figure out why this is the case

Make ec2 inventory plugin Python 3 compatible

update --ansible-private-keyfile to --private-key in documentation