Added layer properties to core and hooked it up with the UI

Implemented timeline caret scrolling logic
Added special treeview style for the layer properties tree

src/Artemis.UI/Converters/LeftMarginMultiplierConverter.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Globalization;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using Artemis.UI.Extensions;
+
+namespace Artemis.UI.Converters
+{
+    public class LeftMarginMultiplierConverter : IValueConverter
+    {
+        public double Length { get; set; }
+
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            var item = value as TreeViewItem;
+            if (item == null)
+                return new Thickness(0);
+
+            return new Thickness(Length * item.GetDepth(), 0, 0, 0);
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}