Just had a good idea how to fix the 'open in new tab' workaround for getting more space on various pages (particularly useful on the status monitor). I've implemented a very quick demonstration on how a collapsible navigation frame could work like. If the idea is good and the feature can go to master, I will implemented it better. Also it could need a better icon.
Commit 5fb7f9cd1716ae747a6e898ee6e92c864d4da6dc and 05dd085aeb0334d1e9ee68037efb563866892164 do the magic. It will make an arrow appear vertically centered on the nav frame. Should be testable anytime soon on http://demo.phpmyadmin.net/gsoc-tyron