support for .NET framework 3.5

Still have bugs

Net35/HandyControlDemo_Net35/UserControl/Main/ContributorsView.xaml

@@ -0,0 +1,14 @@
+<UserControl x:Class="HandyControlDemo.UserControl.ContributorsView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:userControl="clr-namespace:HandyControlDemo.UserControl"
+             DataContext="{Binding ContributorsView,Source={StaticResource Locator}}"
+             Background="{DynamicResource SecondaryRegionBrush}">
+    <ListBox Background="{DynamicResource GitHubDrawingBrush}" ItemContainerStyle="{StaticResource ListBoxItemStyle}" BorderThickness="0" ItemsSource="{Binding DataList}" ItemsPanel="{StaticResource FluidMoveBehaviorWrapPanelItemsPanelTemplate}">
+        <ListBox.ItemTemplate>
+            <DataTemplate>
+                <userControl:Avatar UserName="{Binding UserName}" Link="{Binding Link}" Source="{Binding AvatarUri}"/>
+            </DataTemplate>
+        </ListBox.ItemTemplate>
+    </ListBox>
+</UserControl>