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/Server/WorldSocket.cpp

@@ -19,19 +19,20 @@
 #include "WorldSocket.h"
 #include "AuthenticationPackets.h"
 #include "BattlenetRpcErrorCodes.h"
-#include "BigNumber.h"
 #include "CharacterPackets.h"
+#include "DatabaseEnv.h"
+#include "Errors.h"
 #include "HmacHash.h"
-#include "Opcodes.h"
 #include "PacketLog.h"
-#include "QueryCallback.h"
+#include "Realm.h"
+#include "RBAC.h"
 #include "ScriptMgr.h"
 #include "SessionKeyGeneration.h"
 #include "SHA256.h"
 #include "World.h"
-
+#include "WorldPacket.h"
+#include "WorldSession.h"
 #include <zlib.h>
-#include <memory>
 
 #pragma pack(push, 1)
 
@@ -42,6 +43,8 @@ struct CompressedWorldPacket
     uint32 CompressedAdler;
 };
 
+#pragma pack(pop)
+
 class EncryptablePacket : public WorldPacket
 {
 public:
@@ -53,8 +56,6 @@ private:
     bool _encrypt;
 };
 
-#pragma pack(pop)
-
 using boost::asio::ip::tcp;
 
 std::string const WorldSocket::ServerConnectionInitialize("WORLD OF WARCRAFT CONNECTION - SERVER TO CLIENT");
@@ -995,3 +996,8 @@ bool WorldSocket::HandlePing(WorldPackets::Auth::Ping& ping)
     SendPacketAndLogOpcode(*WorldPackets::Auth::Pong(ping.Serial).Write());
     return true;
 }
+
+bool PacketHeader::IsValidOpcode()
+{
+    return Command < NUM_OPCODE_HANDLERS;
+}