Improve NoDelay reliability.

- Instead of tying NoDelay behavior to OF_JustSpawned, use a new actor
  flag, MF7_HANDLENODELAY. This only gets cleared once it has actually
  been checked by Tick(). This is necessary because freeze mode delays the
  initial run of Tick() past the initial spawn, so OF_JustSpawned will no
  longer be set when it does the initial tick.
- Delay NoDelay processing if an actor is spawned dormant. Actors spawned
  dormant have Deactivate() called before they tick, so MF7_HANDLENODELAY
  will remain set as long as an actor is dormant. This allows the NoDelay
  handling to occur as expected once it is activated.

src/dobject.h

@@ -473,7 +473,7 @@ public:
 	// use this method.
 	virtual size_t PointerSubstitution (DObject *old, DObject *notOld);
 	static size_t StaticPointerSubstitution (DObject *old, DObject *notOld);
-	
+
 	PClass *GetClass() const
 	{
 		if (Class == NULL)