added ability to put a shadow below the stuck view. Updated the README and the sample to reflect this.
made the left offset an Integer
added ability to put a shadow below the stuck view. Updated the README and the sample to reflect this.
Merge branch 'stuckShadow' of https://github.com/parkin1/StickyScrollViewItems into stuckShadow

Conflicts:
	library/src/com/emilsjolander/components/StickyScrollViewItems/StickyScrollView.java
Merge pull request #12 from parkin1/stuckShadow

added shadow feature below the stuck view.