* Mother of all commits:

* Cleaned up copyright notices in AssemblyInfo.cs's
* Added Copyright headers to a bunch of files missing them
* Replaced several common string instances with a static constant to prevent reallocation of the same strings thousands of times. "" -> String.Empty is the first such candidate.

OpenSim/Region/ScriptEngine/DotNetEngine/ScriptManager.cs

@@ -64,7 +64,7 @@ namespace OpenSim.Region.ScriptEngine.DotNetEngine
 
             // We will initialize and start the script.
             // It will be up to the script itself to hook up the correct events.
-            string ScriptSource = "";
+            string ScriptSource = String.Empty;
 
             SceneObjectPart m_host = World.GetSceneObjectPart(localID);