Move over to Logback for the backend
    -Convert the configuration file
    -Convert the AppConfig to configure basic logging
Profile and improve performance for the ConcurrentEngine when looking for similarities.
    -SynchronousEngine is about 2.5x faster currently for finding similarities
    -ConcurrentEngine actors for finding similarities are not CPU constrained and need to be
Convert app configuration format from a java properties to a typesafehub:config
    -Rewrite properties in new format (JSON)
    -Rewrite PropertiesLoader to use the new format
Add functionality to both engines
    -Recursive directory scanning
        -Determine how to handle similarites there... All images or just per folder
    -Move files to new locations
        -Rename new files based on their MD5
Add functionality to ImageService
    -Cache thumbnails
    -Generate thumbnails
    -Move caching of images into the ImageService