Fixes 917588 - restore pre-refactor behaviors

Restores plot onhover behavior, cosmetic space between product and
version in the version selector, and makes some CSS tweaks to restore
a solid color header and reduce wasted horizontal space.

If the "add plot" functionality is restored multiple plots should look
pretty alright.
Merge pull request #11 from lonnen/restore

Fixes 917588 - restore pre-refactor behaviors