changes

added time to allow a sense of passage of time especially when m1 is moving and simulation pause when m1 hits M1 or M2
improved collision detection and pause
//case 2  inside mass1
if (show1==true&&xtest <(x1+size/2)&&xtest>(x1-size/2))
{
  _pause();
  }
//case 3  inside mass2
if (show2==true&&xtest <(x2+size/2)&&xtest>(x2-size/2))
{
  _pause();
  }