4036 Tag set nominations front end improvements

https://code.google.com/p/otwarchive/issues/detail?id=4036

**MERGE AFTER PULL REQUESTS 1735, 1736, and 1737**

Pull requests 1735 and 1736 relate to our fancy JavaScript tooltips, which use a made-up "tooltip" attribute when they'd be better off using "data-tooltip." True, we're not using HTML5 yet, but "tooltip" isn't valid in either XHTML or HTML5. At least "data-tooltip" is valid in one of them.

This fixes the problems detailed in [Issue 4036](https://code.google.com/p/otwarchive/issues/detail?id=4036)... and an unclosed HTML tag, a missing period on a sentence, some missing translation functions on strings, and a random ^ that was at the start of an error message I received.