Finally shattered CObjectHandler.cpp into tiny bits

- This file is now split into multiple smaller files in mapObjects
directory
- CObjectHandler itself now contains only core classes (Handler itself,
CGObject and interfaces)
- Cleaned up excessive #include's through whole project

lib/mapObjects/CRewardableObject.cpp

@@ -15,6 +15,8 @@
 #include "../client/CSoundBase.h"
 #include "NetPacks.h"
 
+#include "CObjectClassesHandler.h"
+
 bool CRewardLimiter::heroAllowed(const CGHeroInstance * hero) const
 {
 	if (dayOfWeek != 0)