handle buttonPressed event in rootViewController

lib/ios/RNNNavigationButtons.m

 		return nil;
 	}
 	
-	barButtonItem.target = self;
+	barButtonItem.target = self.viewController;
 	barButtonItem.action = @selector(onButtonPress:);
 	
 	NSNumber *enabled = [self getValue:dictionary[@"enabled"] withDefault:defaultStyle.enabled];
 	return value ? value : defaultValue;
 }
 
--(void)onButtonPress:(RNNUIBarButtonItem*)barButtonItem {
-	[self.viewController.eventEmitter sendOnNavigationButtonPressed:self.viewController.componentId buttonId:barButtonItem.buttonId];
-}
-
 @end

lib/ios/RNNRootViewController.h

 #import "RNNEventEmitter.h"
 #import "RNNNavigationOptions.h"
 #import "RNNAnimator.h"
+#import "RNNUIBarButtonItem.h"
 
 typedef void (^RNNReactViewReadyCompletionBlock)(void);
 
 
 
 - (instancetype)initWithName:(NSString*)name
-				withOptions:(RNNNavigationOptions*)options
-			withComponentId:(NSString*)componentId
-			rootViewCreator:(id<RNNRootViewCreator>)creator
-			   eventEmitter:(RNNEventEmitter*)eventEmitter
-		  isExternalComponent:(BOOL)isExternalComponent;
+				 withOptions:(RNNNavigationOptions*)options
+			 withComponentId:(NSString*)componentId
+			 rootViewCreator:(id<RNNRootViewCreator>)creator
+				eventEmitter:(RNNEventEmitter*)eventEmitter
+		 isExternalComponent:(BOOL)isExternalComponent;
 
 - (void)applyTopTabsOptions;
 - (BOOL)isCustomViewController;
 - (void)applyModalOptions;
 - (void)optionsUpdated;
 
+-(void)onButtonPress:(RNNUIBarButtonItem *)barButtonItem;
+
 @end

lib/ios/RNNRootViewController.m

 	return actions;
 }
 
+-(void)onButtonPress:(RNNUIBarButtonItem *)barButtonItem {
+	[self.eventEmitter sendOnNavigationButtonPressed:self.componentId buttonId:barButtonItem.buttonId];
+}
+
 /**
  *	fix for #877, #878
  */