Refactor localization using a js templating framework

[ilyapoz]

Someone suggested https://github.com/janl/mustache.js on stackoverflow.

At the moment the tooltips and other attributes are especially annoying to localize: too much duplication.

[ilyapoz]

We can do this now in knockout.js
The tooltips are easily localizeable that way and this is used already.

But do we need to?
For large portions of text/markup html is better anyway.