Replacing custom filtering code with getClientControls()

The previous code was not working properly with the touch scroll
strategy (items were appearing multiple times in the repeater), and
this existing framework feature seems to be what we need here.

Enyo-DCO-1.1-Signed-off-by: Gray Norton <gray.norton@palm.com>
Adding scrollToRow() and scrollToSelected()

These features exist in List, so CollectionList presumably inherits
them, but they needed to be implemented directly in CollectionRepater.
There are probably a bunch more like this.

Enyo-DCO-1.1-Signed-off-by: Gray Norton <gray.norton@palm.com>