Add the Ambient theme to git again

Output/Themes/Ambient/Screens/ScreenTest.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Screen xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <Informations>
+    <ScreenName>ScreenTest</ScreenName>
+    <ScreenVersion>1</ScreenVersion>
+  </Informations>
+  <Backgrounds>
+    <Background Name="Background1">
+      <Type>None</Type>
+      <SlideShowTextures />
+      <Video />
+      <Skin />
+      <Color>
+		<R>0</R>
+		<G>0</G>
+		<B>0</B>
+		<A>1</A>
+      </Color>
+    </Background>
+  </Backgrounds>
+</Screen>