Adding a Topmost setting to login window.

Author: Martin Noreke

Rally.RestApi.UiForWpf/LoginWindow.xaml

@@ -2,7 +2,7 @@
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         Title="LoginControl"
-				x:ClassModifier="internal"
+				x:ClassModifier="internal" Topmost="True"
 				Width="450" MinWidth="350" WindowStartupLocation="CenterScreen">
 	<Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch" x:Name="layoutGrid">
 		<Grid.ColumnDefinitions>