Canvas Image Editing

Added canvas image editing. The image edits are done client-side via
the HTML5 canvas, base64 encoded, and sent to the server.
Merge branch 'master' of https://github.com/binoculars/modular-file-renderer into binoculars-master

Conflicts:
	main.py
	renderer/image/__init__.py
	requirements.txt
extra commit for missed files