title: How to show the system navigation bar in an emulator
body: <p>How can I enable the system navigationbar (the one including the HOME/BACK/MENU) on Jellybean emulator?</p>
  <p>Googling this, somebody said it can be done by changing the property <code>qemu.hw.mainkeys</code>, however I can't find where to set this constant.
  can somebody help me?</p>