New color to brush converter

New boolean to visibility converter
Base class to handle property changes notifications for all View Models
Template selector to handle a different first item in listviews or gridviews

ModernKeePass/Converters/BooleanToVisibilityConverter.cs

@@ -0,0 +1,28 @@
+using System;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Data;
+
+namespace ModernKeePass.Converters
+{
+    public class BooleanToVisibilityConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, string language)
+        {
+            var boolean = value is bool ? (bool) value : false;
+            return boolean ? Visibility.Visible : Visibility.Collapsed;
+        }
+
+        // No need to implement this
+        public object ConvertBack(object value, Type targetType, object parameter, string language)
+        {
+            var visibility = value is Visibility ? (Visibility) value : Visibility.Visible;
+            switch (visibility)
+            {
+                case Visibility.Visible: return true;
+                case Visibility.Collapsed: return false;
+                default:
+                    throw new ArgumentOutOfRangeException();
+            }
+        }
+    }
+}