Crop Uploading

# What's Changed
* Created a much [more dynamic crop image uploader](https://www.dropbox.com/s/7o627ovwcwyg0l8/Crop%20Upload.mov?dl=0). Unfortunately (fortunately?) github doesn't allow inline movies.
* Showed multiple images on the crop page.

# What's Next
* Use this newly earned knowledge and do the same for guides and stages.