Set shadow properties after view has been instantiated.
Fix right area being draggable when only rear VC is set

Disallow dragging border from the right if only rear controller is set, and vise versa when right is set but not rear.
shadow properties
shadow properties
Merge branch 'master' of https://github.com/jackwu95/SWRevealViewController into jackwu95-master
draggableBorderAllowing
v2.0.1