@Override
	public View getExpandToggleButton(View parent) {
		return parent.findViewById(toggle_button_id);
	}
ListAdapter that adds sliding functionality to a list.
Uses R.id.expandalbe_toggle_button and R.id.expandable id's if no
ids are given in the contructor.

@author tjerk
@date 6/13/12 8:04 AM
library/src/main/java/com/tjerkw/slideexpandable/library/SlideExpandableListAdapter.java