Use empty default name for cloned material in the script API.

Docs/ScriptAPI.dox

@@ -1705,7 +1705,7 @@ Methods:<br>
 - void SetUVTransform(const Vector2&, float, const Vector2&)
 - void SetUVTransform(const Vector2&, float, float)
 - void RemoveShaderParameter(const String&)
-- Material@ Clone(const String&) const
+- Material@ Clone(const String& arg0 = String ( )) const
 
 Properties:<br>
 - ShortStringHash type (readonly)

Engine/Engine/GraphicsAPI.cpp

@@ -351,7 +351,7 @@ static void RegisterMaterial(asIScriptEngine* engine)
     engine->RegisterObjectMethod("Material", "void SetUVTransform(const Vector2&in, float, const Vector2&in)", asMETHODPR(Material, SetUVTransform, (const Vector2&, float, const Vector2&), void), asCALL_THISCALL);
     engine->RegisterObjectMethod("Material", "void SetUVTransform(const Vector2&in, float, float)", asMETHODPR(Material, SetUVTransform, (const Vector2&, float, float), void), asCALL_THISCALL);
     engine->RegisterObjectMethod("Material", "void RemoveShaderParameter(const String&in)", asMETHOD(Material, RemoveShaderParameter), asCALL_THISCALL);
-    engine->RegisterObjectMethod("Material", "Material@ Clone(const String&in) const", asFUNCTION(MaterialClone), asCALL_CDECL_OBJLAST);
+    engine->RegisterObjectMethod("Material", "Material@ Clone(const String&in cloneName = String()) const", asFUNCTION(MaterialClone), asCALL_CDECL_OBJLAST);
     engine->RegisterObjectMethod("Material", "void set_numTechniques(uint)", asMETHOD(Material, SetNumTechniques), asCALL_THISCALL);
     engine->RegisterObjectMethod("Material", "uint get_numTechniques() const", asMETHOD(Material, GetNumTechniques), asCALL_THISCALL);
     engine->RegisterObjectMethod("Material", "Technique@+ get_technique(uint)", asMETHOD(Material, GetTechnique), asCALL_THISCALL);