Make contributor bar more efficient

I've rewritten most of the contributor bar stuff.  Here's how I've made it more efficient:

1.  Using event delegation instead of assignment to each individual link.
2.  I'm never querying for elements before I need them, thanks to adding a classname for both shown and hidden elements, as well as using a data-attribute to track that.
3.  Un-nesting CSS for this block.

Let me know if you have questions.
just FYI, passing in a count parameter into the trans template tag is needed to give the underlying i18n system an idea what the count is and when to show which plural form. remember, there are language with as much as 6 plural forms, for example :)