Some bugfixes

Please review my changes and pull them if possible.

I don't know exactly what the intention was in AdapterDataSetObserver.onChanged if lazyload is set. It did not work for me as it realigned the first visible position after a load, which IMHO should not happen.
With my small changes, the list works great for me. 
* No crashes on retained fragments after orientation change
* Proper lazy loading, not on every drag movement
* Gradle support for Android Studio