Started work on manual image cropping
Made 'done' link a button
Imports cleanup
Don't allow users without permission to edit the image to see its focal point chooser
Tests for focal point chooser view
Removed focal point chooser modal and field
Implemented manual image cropping in edit preview
Minor code tweaks
styling and responsive solution for focal point chooser
Merge remote-tracking branch 'torchbox/master' into feature/manual-image-cropping

Conflicts:
	wagtail/wagtailimages/tests.py
Merge pull request #602 from kaedroho/feature/manual-image-cropping

Manual image cropping
Changelog and release notes for manual image cropping
Merge remote-tracking branch 'upstream/master'