Fix Panel ListView hover/focus rect image rect.

Convert UI.png back to PNG8 format (8-bit colormap, non-interlaced).
Correct sample material path.

Bin/Data/UI/DefaultStyle.xml

@@ -185,6 +185,7 @@
     <element type="PanelView" style="ListView" auto="false">    <!-- todo: rename this to PanelListView -->
         <element type="BorderImage" internal="true">
             <attribute name="Image Rect" value="48 16 64 32" />
+            <attribute name="Hover Image Offset" value="16 0" />
             <element internal="true">
                 <attribute name="Layout Spacing" value="4" />
                 <attribute name="Layout Border" value="4 4 4 4" />