Core/Game: Include cleanup

* Mostly aimed at removing Log/DatabaseEnv includes from other headers
* Fix most packet headers including other packet headers - moved common structures such as ItemInstance to their own files
* Moved SAI function definitions to source files (massive or requiring many different dependencies)

src/server/game/Entities/DynamicObject/DynamicObject.cpp

@@ -17,14 +17,13 @@
  */
 
 #include "Common.h"
-#include "Opcodes.h"
-#include "World.h"
-#include "ObjectAccessor.h"
-#include "DatabaseEnv.h"
 #include "GridNotifiers.h"
 #include "GridNotifiersImpl.h"
+#include "Log.h"
+#include "ObjectAccessor.h"
 #include "ScriptMgr.h"
 #include "Transport.h"
+#include "World.h"
 
 DynamicObject::DynamicObject(bool isWorldObject) : WorldObject(isWorldObject),
     _aura(NULL), _removedAura(NULL), _caster(NULL), _duration(0), _spellXSpellVisualId(0), _isViewpoint(false)