Figure out git url shortening long-term

[examknow]

#339 was implemented as a temporary solution to #338 but we ideally should have a sustainable way to do URL shortening with the git modules long term. I was thinking we could borrow the implementation from the shorturl module and allow the user to decide who they want to handle their url shortening (or if they even want to shorten urls at all). This way we can eliminate 100% reliance on any single third party who could end service at any time (cough cough: github).

[examknow]

Probably also should have a catch-all exception handler so that if a shortener breaks, the functionality won't just fail mysteriously.