Added API method 'copyImage' to the MachineImageSupport (grid-api issue #656)
copyImage: copying from current to target region (grid-api issue #656)
Minor javadoc change to clarify field in ImageCopyOptions.
Added a method to copy ProviderContext with a regionId replaced by new value (grid-api issue #656)
Merge branch 'issue-656' of github.com:TheWeatherCompany/dasein-cloud-core into issue-656
Merge pull request #82 from TheWeatherCompany/issue-656

copyImage method for machine images.