Added docker_facts for image and container info

Hi there! This is the docker_facts module, cleaned up, pep8/pyflakes ready for review. 
At this line the module variable is undefined, thus:

invalid output was: Traceback (most recent call last):
  File "/home/dan/.ansible/tmp/ansible-tmp-1410711545.01-2248601240042/docker_facts", line 1412, in <module>
    main()
  File "/home/dan/.ansible/tmp/ansible-tmp-1410711545.01-2248601240042/docker_facts", line 219, in main
    module.fail_json(msg=
UnboundLocalError: local variable 'module' referenced before assignment