More work in preparing for lua-based keyboard controller

Modified ScriptManager to decouple adding libraries from registering libraries
Allowing ScriptManager to register libraries to other lua states as well

src/engine/openspaceengine.cpp

@@ -283,14 +283,14 @@ bool OpenSpaceEngine::initialize() {
 	
     FactoryManager::initialize();
 
-    scriptEngine().initialize();
-
 	// Register Lua script functions
 	LDEBUG("Registering Lua libraries");
 	scriptEngine().addLibrary(RenderEngine::luaLibrary());
 	scriptEngine().addLibrary(SceneGraph::luaLibrary());
 	scriptEngine().addLibrary(Time::luaLibrary());
 
+	scriptEngine().initialize();
+
     // Load scenegraph
     SceneGraph* sceneGraph = new SceneGraph;
     _renderEngine.setSceneGraph(sceneGraph);