add django-image-tools for profile picture images

[#76601086]
revise profile pic model to use django-image-tool Image model

[#76601086]
convenience method for accessing profile pic via rdfperson
adjust bio browse & view pages for profile pic model change

[#76601086]
display profile pictures on home page in random order

needs some refinment from @kevinglover

[#76601086]
fix template error
fixture for image sizes and filters (first pass)

could probably use some refinement from @kevinglover

[#76601086]
initial south migration for profile picture db model
Merge branch 'develop' into feature/image-tools

Conflicts:
	belfast/people/models.py
	belfast/settings.py
tweak new profilepicture model and set up migrations
tweak new profilepicture model and set up migrations
refine profile pic migration
tweak migration to try to initialize Images better
adjust people list and profile template for change to profile model
update home page images to work with tweaked profile pic model
Merge branch 'feature/image-tools' into develop
specify version of django-image-tools so install doesn't fail
add image of old BG site home page, used in overview essay
change thumbnail size to 220x220

addresses blurriness on bios page, recommended by @kevinglover