Square aspect ratio. Ants auto-appear.

Set the aspect ratio of the crop selection to always be 1:1, keeping it square.

Auto-select part of the image to be cropped.

Fix an ID mis-assignment.
Show auto-cropped preview. DRY refactoring.

Show the cropped preview of the auto-selected part of the uploaded image.

Refactor the auto-cropping selection and onload call to #updatePreview to both pull from defaultCropBox.