More lightweight redrawing.

I could not find any szenario in which this solution isn't sufficient. But I and many others (see issues) run into problem with the old solution, which requires two full repaints.

https://github.com/weblinc/jquery.smoothState.js/issues/75
https://github.com/weblinc/jquery.smoothState.js/issues/82
https://github.com/weblinc/jquery.smoothState.js/issues/38
https://github.com/weblinc/jquery.smoothState.js/issues/37