Detach accordions from .card

Created by: moso

I'm having some fun with v4 alpha 6, however, is there a specific reason why the collapse groups, aka accordions, are hooked up on .cards?

Ideally, I would be able to make my own collapse grouping like this (simplified, but you will get my idea):

<div id="accordion">
  <h3>
    <a data-toggle="collapse" data-parent="#accordion" href="#collapseOne" aria-expanded="true" aria-controls="collapseOne">
      Item One
    </a>
  </h3>
  <div id="collapseOne" class="collapse show">
    <ul class="list-unstyled">
      <li>Item</li>
      <li>Item</li>
      <li>Item</li>
      <li>Item</li>
    </ul>
  </div>

  <h3>
    <a data-toggle="collapse" data-parent="#accordion" href="#collapseTwo" aria-expanded="false" aria-controls="collapseTwo">
      Item Two
    </a>
  </h3>
  <div id="collapseTwo" class="collapse">
    <ul class="list-unstyled">
      <li>Item</li>
      <li>Item</li>
      <li>Item</li>
      <li>Item</li>
    </ul>
  </div>

  [...]

</div>

This would allow us to use collapse groupings on other than cards. The same thing was an annoying issue with 3.x where they are hooked up on panels.