Fix NPE in Loader's onReset()
We were removing current result's cursor from WeakHashMap in deliverResult,
so we couldn't access it later in onReset().
Also added a nullcheck for Cursor since ContentResolver may return null.
Properly handle old result which is associated to null Cursor
Never return null from your Function passed to ComposedCursorLoader
slight formatting change
version bump - 0.0.2