Update navigation bar's title and tint color on #resetTo / #replace.

* Approach borrowed from: facebook#1403 (comment)

* Would need to follow similar pattern to update other navigation / nav bar props on resetTo / replace,
  but want to limit the changes from RN master for now.

React/Views/RCTNavItem.h

@@ -8,12 +8,13 @@
  */
 
 #import <UIKit/UIKit.h>
-
+#import "RCTWrapperViewController.h"
 #import "RCTComponent.h"
 
 @interface RCTNavItem : UIView
 
 @property (nonatomic, copy) NSString *title;
+@property (nonatomic, weak) RCTWrapperViewController *delegate;
 @property (nonatomic, strong) UIImage *leftButtonIcon;
 @property (nonatomic, copy) NSString *leftButtonTitle;
 @property (nonatomic, strong) UIImage *rightButtonIcon;

React/Views/RCTNavItem.m

@@ -11,10 +11,27 @@
 
 @implementation RCTNavItem
 
+@synthesize delegate = _delegate;
 @synthesize backButtonItem = _backButtonItem;
 @synthesize leftButtonItem = _leftButtonItem;
 @synthesize rightButtonItem = _rightButtonItem;
 
+- (void)setTitle:(NSString *)title
+{
+  if (title != _title) {
+    _title = title;
+    [self.delegate titleDidChange:title];
+  }
+}
+
+- (void)setBarTintColor:(UIColor *)barTintColor
+{
+  if (barTintColor != _barTintColor) {
+    _barTintColor = barTintColor;
+    [self.delegate barTintColorDidChange:barTintColor];
+  }
+}
+
 - (void)setBackButtonTitle:(NSString *)backButtonTitle
 {
   _backButtonTitle = backButtonTitle;

React/Views/RCTWrapperViewController.h

@@ -26,6 +26,9 @@ didMoveToNavigationController:(UINavigationController *)navigationController;
 - (instancetype)initWithContentView:(UIView *)contentView NS_DESIGNATED_INITIALIZER;
 - (instancetype)initWithNavItem:(RCTNavItem *)navItem;
 
+- (void)titleDidChange:(NSString *)title;
+- (void)barTintColorDidChange:(UIColor *)barTintColor;
+
 @property (nonatomic, weak) id<RCTWrapperViewControllerNavigationListener> navigationListener;
 @property (nonatomic, strong) RCTNavItem *navItem;
 

React/Views/RCTWrapperViewController.m

@@ -45,6 +45,7 @@ - (instancetype)initWithNavItem:(RCTNavItem *)navItem
 {
   if ((self = [self initWithContentView:navItem])) {
     _navItem = navItem;
+    _navItem.delegate = self;
   }
   return self;
 }
@@ -60,6 +61,19 @@ - (void)viewWillLayoutSubviews
   _currentBottomLayoutGuide = self.bottomLayoutGuide;
 }
 
+
+- (void)titleDidChange:(NSString *)title
+{
+  UINavigationItem *item = self.navigationItem;
+  item.title = title;
+}
+
+- (void)barTintColorDidChange:(UIColor *)barTintColor
+{
+  UINavigationBar *bar = self.navigationController.navigationBar;
+  bar.barTintColor = barTintColor;
+}
+
 static BOOL RCTFindScrollViewAndRefreshContentInsetInView(UIView *view)
 {
   if ([view conformsToProtocol:@protocol(RCTAutoInsetsProtocol)]) {