Added a global action bar to maintain action bar menu item ordering.

  Effected Files:
    FragmentHierarchicalNavigation\FragmentA.cs
    FragmentHierarchicalNavigation\FragmentB.cs
    FragmentHierarchicalNavigation\FragmentNavEx.csproj
    FragmentHierarchicalNavigation\Main.cs
    FragmentHierarchicalNavigation\Resources\Resource.Designer.cs
    FragmentHierarchicalNavigation\Resources\Menu\action_bar.xml