[sample] add image in item to show jumping bug.

Add some images in sample to show jumping bug.
Case 1:
scroll down, and when images are loaded RecyclerView jump to the first visible position.
The bug is present in all LayoutManager.
Case 2: scroll to the top of the RecyclerView, a gap is appear between first item and RecyclerView.
The bug is present in the GridLayoutManager and the SpannableLayoutManager.

The sample illustrates now the bug trying to be fixed in the PR  #167

Enjoy animals :)

![device-2014-11-28-161355](https://cloud.githubusercontent.com/assets/3284106/5229638/041734c4-771b-11e4-8602-b6b9ce79c7bc.png)