Fix CollectionView.arrayDidChange documentation

CollectionView.arrayDidChange arguments have changed wihout
documentation changes. This commit fixes this method documentation.
Merge pull request #2579 from karlguillotte/collection-view-docs

Fix CollectionView.arrayDidChange documentation
fix rejecting a deferred with itself
cleanup deferred tests
Merge pull request #2580 from stefanpenner/master

fix rejecting a deferred with itself