title: Replace MsTest with xUnit
body: <p>While moving from MsTEst to xUnit VS2012 plugin I still can see my old MsTest in Test Explorer Window.</p>
  
  <p>Does xUnit VS add on supports MsTest?</p>
  
  <p>Does VS is able to work with 2 unit test providers in simultaneously?</p>
  
  <p>Can I disable MsTest?</p>
  
  <p>Thank you</p>