Ground work for Wino Calendar. (#475)

Wino Calendar abstractions.

Wino.Calendar/Styles/CalendarDayItemsControl.xaml

@@ -0,0 +1,21 @@
+<ResourceDictionary
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:controls="using:Wino.Calendar.Controls">
+
+    <!--  Calendar day items.  -->
+    <Style TargetType="controls:CalendarDayItemsControl">
+        <Style.Setters>
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="controls:CalendarDayItemsControl">
+                        <controls:WinoCalendarPanel
+                            x:Name="PART_CalendarPanel"
+                            DayModel="{TemplateBinding DayModel}"
+                            EventItemMargin="0" />
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style.Setters>
+    </Style>
+</ResourceDictionary>