Pull in images from Category:Images_with_borders to landing page of CropTool when no file is provided

[jaredzimmerman]

to give users quick access to images needing improvement.

provide a way for a user to say "This image doesn't need to be cropped" which removes the Category:Images_with_borders without cropping.

After successful crop provide a text link to "Improve more images?" which loads the next or random image from Category:Images_with_borders