Splitup wagtailimages utils
Refactored crop_to_centre actions to use a utils method
Added ability to crop to a point or multiple weighted points
Added smartcropping with basic feature detection
Removed stray print statement
Added face detection
Many improvements to smart cropping
Added docs for 'smart' image resizing method
Cleanup
Moved some smartcropping code into feature_detection
Refactored feature detection code into a class
Added focal point fields
Moved smartcropping code from image backends into image model
Make image processing backends use focal_point
Made image processing code focal point aware
Removed old docs
Fixed missing future import
Moved extra room calculation into get_suggested_focal_point
Run smartcropping calculations on image save
Set default focal point key in filenames to 'focus-none'

This prevents filenames being generated with '..'