[Bootstrap] 把內建的carousel滑動效果改成fade-in/fade-out效果

來源網址:
http://stackoverflow.com/questions/18548731/bootstrap-3-carousel-fading-to-new-slide-instead-of-sliding-to-new-slide

/* Fade transition for carousel items */
.carousel .item {
    left: 0 !important;
      -webkit-transition: opacity .4s; /*adjust timing here */
         -moz-transition: opacity .4s;
           -o-transition: opacity .4s;
              transition: opacity .4s;
}
.carousel-control {
    background-image: none !important; /* remove background gradients on controls */
}
/* Fade controls with items */
.next.left,
.prev.right {
    opacity: 1;
    z-index: 1;
}
.active.left,
.active.right {
    opacity: 0;
    z-index: 2;
}