Feature: Scale images

[joelso]

Expose an API for scaling, cropping images on-the-fly
File service could expose an API for the client when images are retrieved.

• GET /a-bus.jpg?w=400 - Should use query for width, height is based on the image aspect ratio
• GET /a-bus.jpg?w=400&h=300 - Should take the biggest value of w / h and use that.

• Each image that are created should be cached and saved on S3 and this should be used first.
  • Should use HEAD request when checking if image exists.
  • File service should act as a proxy for S3.
• Should add option for proxy mode.
• In memory url table cache to avoid several requests to S3 to see if cached image exists.