Fix list-dividers use data-theme attribute first

[dotnetwise]

Allow the list-divider to customize its own theme if desired

<ul data-role="listview" data-divider-theme="e">
<li data-role="list-divider">Theme e</li>
<li>some value</li>
<li data-role="list-divider" data-theme="b">Theme b</li>
<li>some other value</li>
</ul>

[jaspermdegroot]

@dotnetwise

Thanks for the PR. I think we should land this.

Did you run the listview unit tests?

[jerone]

+1 for landing.

[jaspermdegroot]

I ran the listview unit test... merging

[dotnetwise]

Thanks!