ListView: Prevent unregisterItem method to delete item from listView

When I delete an item from listView, two deletion operation was occurring as: one under listViewController->unregisterItem, the other one in listView->removeItem

Not sure if it is ok to remove this line from listViewController, but again as a counterpart, i expect registerItem to add item to listView, but it is not. 

Also i did not see any other add/remove operator in listViewController, so I deleted it with the tests. :) 
Can we remove the `actualIndex` variable as well. Other than tat, LGTM.