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/mapping/CMap.cpp

@@ -7,6 +7,7 @@
 #include "../CTownHandler.h"
 #include "../CHeroHandler.h"
 #include "../mapObjects/CObjectClassesHandler.h"
+#include "../mapObjects/CGHeroInstance.h"
 #include "../CGeneralTextHandler.h"
 #include "../CSpellHandler.h"
 #include "CMapEditManager.h"