Added serializer-based class able to make deep copies of objects — CMemorySerializer.

CGameState::init will work on the deep copy of StartInfo.
Some casts to reduce warnings.

lib/NetPacksBase.h

@@ -17,7 +17,7 @@ class CStackInstance;
 class CArmedInstance;
 class CArtifactSet;
 class CBonusSystemNode;
-class ArtSlotInfo;
+struct ArtSlotInfo;