Side-by-side diff as a first class citizen

Currently side-by-side diff can be viewed in a modal window, 1 changed file at a time.

It would be nice to have that as a first class diff view, like current unified one. I mean in the main window with all the files viewed in side-by-side fashion.

Additionally pretty useful would be if side-by-side diff could be set as a default for viewing changeset changes. So one wouldn't need to click some button all the time.