[mr2868] Cosmetic changes, GUID -> Guid
[mr2869] EventAI: 1) some speed up in ProcessEvent (not need call ProcessAction if no action). 2) Out more info if creature has EventAI and SD2 script.
[mr2870] Some cosmetics for Item.cpp and fix DeleteLootFromDB()
[mr2871] Initialize forgotten variable
[mr2872] Show error in client, if potion not accepted by character class