fix foursquare image urls

dict comes down looking like
{'prefix': 'https://irs2.4sqi.net/img/user/', 'suffix': '/4a99644f3ace0.jpg'}, 'a

images look like

https://irs2.4sqi.net/img/user/128x128/4a99644f3ace0.jpg
Updating docs to reflect need for HTTP method overriding when removing social connections.
Adding a little bit about making connections unique via a Uniqueness constraint on the Connections DB model.
docs-fix: change Connection.user to relationship in documentation
Merge branch 'master' into develop
Post-login session key config option is now respected.
Merge pull request #49 from maligree/develop

Post-login session key config option is now respected.
Merge pull request #46 from jquacinella/develop

Updating docs to reflect need for HTTP method overriding when removing s...
update to get unsized image
Merge branch 'blackmad-develop' into develop