Allow entities and nodes to update while the game is paused.

Added Lua functions:
- node_setPauseFreeze()
- entity_setPauseFreeze()
- getFPS()

Also fixed possible crash in entity_setStateTime().

Aquaria/Path.h

@@ -144,6 +144,7 @@ public:
 
 	bool effectOn;
 	bool spiritFreeze;
+	bool pauseFreeze;
 
 	PathShape pathShape;