Remove unused triangle sprite.

osu.Game.Resources/osu.Game.Resources.csproj

@@ -127,9 +127,6 @@
   <ItemGroup>
     <EmbeddedResource Include="Textures\Play\osu\ring-glow%402x.png" />
   </ItemGroup>
-  <ItemGroup>
-    <EmbeddedResource Include="Textures\Play\osu\triangle%402x.png" />
-  </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="Fonts\Exo2.0-Black.fnt" />
     <EmbeddedResource Include="Fonts\Exo2.0-BlackItalic.fnt" />
@@ -204,9 +201,7 @@
   <ItemGroup>
     <EmbeddedResource Include="Samples\Menu\heartbeat.mp3" />
   </ItemGroup>
-  <ItemGroup>
+  <ItemGroup />
-    <Folder Include="Samples\Sliderbar\" />
-  </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="Samples\Gameplay\drum-hitclap.wav" />
     <EmbeddedResource Include="Samples\Gameplay\drum-hitfinish.wav" />