accomodate position difference when containment is specified

Author: mnzaki

src/angular-sortable-view.js

@@ -444,6 +444,9 @@
 								targetLeft = containmentRect.left + body.scrollLeft;
 							if(targetLeft + helperRect.width > containmentRect.left + body.scrollLeft + containmentRect.width) // right boundary
 								targetLeft = containmentRect.left + body.scrollLeft + containmentRect.width - helperRect.width;
+
+              targetLeft -= containmentRect.left;
+              targetTop  -= containmentRect.top;
 						}
 						this.style.left = targetLeft - body.scrollLeft + 'px';
 						this.style.top = targetTop - body.scrollTop + 'px';
@@ -622,4 +625,4 @@
 		};
 	}
 
-})(window, window.angular);
+})(window, window.angular);