Flexible font-size for huge text in sign_in page

A workaround to have a flexible font-size for huge text in the sign_in page. To prevent text overflows/wraps with long pod names (some pods have the name unreadable in their sign_in page) . After trying uselessly some jquery plugin to fit text I wrote this one that seems to work good. We can use it waiting to find a better solution.

![login_screen_huge_text](https://cloud.githubusercontent.com/assets/914785/3474609/ed78de6a-02e5-11e4-9608-af7e7af908be.jpg)

So this is the last issue :) We really don't want to add more inline JS as we're trying to get rid of it. You should be able to hook your code up by adding a route [here](https://github.com/diaspora/diaspora/blob/develop/app/assets/javascripts/app/router.js#L2) and placing it in the new router function.