Barbara Ramiro I did some cleanup and (hopefully) improvements in the header and page-nav rendering to display both language selector and the login/user menu. Please note that some CSS classes and overall structure we had there is now different (no more "status" class etc). But it should be cleaner now. I put as much as possible into the layout files, should you want to improve the styling yet. I tried to make sure I did not miss any rtl and responsive styling there, but we will need to double check that.
You may also note a new "mixins.less" file created. The reason for that is that at the front page, the login+language selector (called "usertools" now) are part of the header, while in all other layout files they are part of the page-navbar. So, to be able to share the CSS for both locations, having a mixin seemed to be the best way. Let's see, maybe you will need to redesign the overall structure a bit yet while working on the sticky footer (as you mentioned).