title: Font Awesome "Cog" spins unevenly
body: <p>We are using  and adding/removing fa-spin on certain js events. The problem, which is easily visible at 3x, is that the cog does not spin around a fixed axis. I suspect this is because the icon itself (SVG) is reported by Chrome at 42 x 49 pixels, even though the image is visually square. Any suggestions to work around this issue?</p>
  
  <p>It is subtle but noticeable:
  <a href="http://www.screencast.com/t/NwJTcKe4o" rel="noreferrer">http://www.screencast.com/t/NwJTcKe4o</a> </p>