Add an import action to the Image LWRP
Add non-stdin docker build support to :build image action
README updates for new LWRP functionality
Fix import action to match docker docs. Prefer dockerfile over image_url in build action
Fix README example for image import with repo/tag attributes
Merge pull request #20 from wingrunr21/add_image_import_action

Add docker import and non-stdin docker build support to image LWRP