Added Themes + Toggle

PolyChat/Views/Dialog.xaml.cs

@@ -36,6 +36,7 @@ namespace PolyChat.Views
             Secondary = secondary.Action;
             // show
             MainPage.SafelyOpenDialog(this);
+            RequestedTheme = MainPage.GetTheme();
         }
 
         private void setType(string type, string message)

PolyChat/Views/EditUsernameDialog.xaml.cs

@@ -22,6 +22,7 @@ namespace PolyChat.Views
             if (initialValue == null || initialValue.Length == 0) IsSecondaryButtonEnabled = false;
             else  input.Text = initialValue;
             validate();
+            RequestedTheme = MainPage.GetTheme();
         }
 
         public string getValue()

PolyChat/Views/NewChatDialog.xaml.cs

@@ -20,6 +20,7 @@ namespace PolyChat.Views
         {
             this.InitializeComponent();
             IsPrimaryButtonEnabled = false;
+            RequestedTheme = MainPage.GetTheme();
         }
 
         public string getValue()