Added support for HeaderListViewAdapter in SpiceListView.

The current behavior throws a ClassCastException ungracefully on ListView#setAdapter when a header has been added using the ListView#addHeaderView method. The issue is, Android automatically wraps the adapter to a http://developer.android.com/reference/android/widget/HeaderViewListAdapter.html in that scenario.

The improvement is that the SpiceListView deals correctly with that issue by examining he instance class of the adapter and acting accordingly.