New typeface + few modifications, right margin, tabbar context menu

Hi. I didn't like the look so i reskinned it + made few small impovements. Should be retina ready.
I've added a link to the icons website as it is described on http://icons8.com/license/
The diff is easier than it migh look.

This is how it looks:
https://www.dropbox.com/s/8iij6fjwi4v6f2g/cats.png
https://www.dropbox.com/s/ow34wm66lh9jyxv/clouds_midnight.png