Hover display of footnotes

[dlschwartz]

How difficult is it to build a footnote display when you hover over the superscripted pointer in the body? I'm not certain we want this, but I think this could be a good feature. Let me know if we should discuss this before we implement anything.

[wsalesky]

This is pretty easy. We have it for the corpus, so it is just a matter of porting over the necessary code changes. The current code is mostly just straight from the TEI website, so there is lots of room for improvement, but I want to make sure to keep the customizations separate, so it is easy to update both parts.