Implement listing images
Create an ImageFetcherStorer for the API
Synchronise and display the AMI descriptions

These contain timestamps for many of our images, which makes it easier to spot
old ones.
Synchronise and display the AMI state
Fix a typo/syntax error in the image syncing code
Synchronise image name instead of description

We don't use the description, but we do use the name, which is what I meant to
synchronise all along.
Auto-merged master into hh-images on deployment.
Merge pull request #16 from travis-ci/hh-images

Implement listing images