Change Navigation Bar Background (Tint) Color to Axai Blue (#428BCA)
* App.cs: Add MemberDetails 

* Axai.sln:
* App.cs:
* Axai.csproj:
* AppDelegate.cs:
* TabbedPage.xaml:
* MembersPage.xaml:
* TabbedPage.xaml.cs:
* MemberDetails.xaml:
* MembersPage.xaml.cs:
* MemberDetails.xaml.cs:
* Axai.Android.csproj: