Include default methods for nextState and setState

AppKit/CPControl.j

@@ -301,6 +301,15 @@ var CPControlBlackColor     = [CPColor blackColor];
     [self highlight:NO];
 }
 
+- (void)setState:(int)state
+{
+}
+
+- (int)nextState
+{
+    return 0;
+}
+
 - (unsigned)mouseDownFlags
 {
     return _trackingMouseDownFlags;