Add user karma for alternate accounts

Implemented part of a [desired feature request](http://www.reddit.com/r/Enhancement/comments/1ki5ve/feature_request_show_linkcomment_karma_and/). However, although this feature is functional, it still needs some work. In particular, caching and over-calling the API is still a major issue here--`$.get` caches calls (so karma isn't always up-to-date), and excessive calls are made, especially if the user does not use the account switcher. Would there be a way to perhaps cache karma and a time into `localStorage`, and trigger this whenever some clicks on the account switcher (rather than on page load)? (I'm not too familiar with using RES's storage.)