Fixed an iOS9 issue with CCScrollView whereby gesture recognisers that were not being removed when the node was hidden, or removed from the node tree were being added a second time. iOS8 and earlier allowed this even though it wasn't correct. iOS 9 prevents this from working anymore.

Author: pkclsoft

cocos2d-ui/CCScrollView.m

@@ -768,8 +768,14 @@ - (void) onEnterTransitionDidFinish
 
     NSMutableArray* recognizers = [view.gestureRecognizers mutableCopy];
     if (!recognizers) recognizers = [NSMutableArray arrayWithCapacity:2];
-    [recognizers insertObject:_panRecognizer atIndex:0];
-    [recognizers insertObject:_tapRecognizer atIndex:0];
+    
+    if ([recognizers containsObject:_panRecognizer] == NO) {
+        [recognizers insertObject:_panRecognizer atIndex:0];
+    }
+    
+    if ([recognizers containsObject:_tapRecognizer] == NO) {
+        [recognizers insertObject:_tapRecognizer atIndex:0];
+    }
 
     view.gestureRecognizers = recognizers;
     [super onEnterTransitionDidFinish];