ISSUE-2824 Adding user_data to rackspace provider
fixed misspelling

`settng` should be `setting`
Merge pull request #2855 from berendt/fix_typo_settng

fixed misspelling
Merge pull request #2826 from yannh/rackspace_cloud_init

ISSUE-2824 Adding user_data to rackspace provider
[google|compute] Update Images support

- Add missing "Image" properties
- Add "ready?" method to model
- Add "destroy" method to model
- Use "Operation" instead of the "backoff_if_unfound" method when inserting an "Image"
Merge branch 'gce_images' of github.com:frodenas/fog into gce_images