Use overlay wrapper for waves and its ripple effect

[fians]

I think it would be good if Waves create an overlay wrapper element inside an actual element and put all the ripple effect child there.

Instead doing this:

<a href="#" class="waves">
  This is button
  <i class="ripple"></i>
  <i class="ripple"></i>
  <i class="ripple"></i>
</a>

Waves should doing like this:

<a href="#" class="waves">
  This is button
  <span class="wrapper">
    <i class="ripple"></i>
    <i class="ripple"></i>
    <i class="ripple"></i>
  </span>
</a>

[fians]

I think this will fix #147, #132 and I hope it also fix bootstrap issue on #144

[miguelcobain]

This would be very helpful.