title: QTabWidget setCornerWidget with expanding width
body: <p>I simply want the cornerWidget of a QTabWidget to expand its width as mush as possible. I have tried setting the QSizePolicy to {Expanding, Expanding} but I can't get it to work. I want to have some tabs to the left and a widget occupying all left over space to the right.</p>
  
  <p>I can get it to occupy a fix width by overriding the sizeHint, but that's not dynamically resizing. Anyone know how to do this? Is it a bug in Qt?</p>
  
  <p>I'm using Qt 5.0.2 in Linux.</p>