support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Themes/Styles/ScrollViewer.xaml

@@ -0,0 +1,14 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    xmlns:controls="clr-namespace:HandyControl.Controls">
+
+    <ResourceDictionary.MergedDictionaries>
+        <ResourceDictionary Source="Base/ScrollViewerBaseStyle.xaml"/>
+    </ResourceDictionary.MergedDictionaries>
+
+    <!--default style-->
+    <Style BasedOn="{StaticResource ScrollViewerNativeBaseStyle}" TargetType="ScrollViewer"/>
+
+    <Style BasedOn="{StaticResource ScrollViewerBaseStyle}" TargetType="controls:ScrollViewer"/>
+
+</ResourceDictionary>