Ribbon for IRC link

This adds a ribbon based on @oiami's work, implemented using CSS.

Screenshot:
![moo_-_minimalist_object_orientation_ with_moose_compatibility _-_metacpan org_-_2014-09-14_03 01 25](https://cloud.githubusercontent.com/assets/50029/4263347/cb202652-3bde-11e4-9727-2e206ffda8c9.png)

Addressed #1235