[outdated] WorldMap - mapIDs, detection when map is changed

[Garkin]

1. Currently there is no easy way to identify maps. Please add something like GetMapID() that will return unique ID, so I do not need use workarounds like determining location from name of map textures.
   
   
2. Add some way to find out that map was changed. Event EVENT_ZONE_CHANGED does not mean that there is different map now.
   We have to use workarounds like check in some OnUpdate loop if there is different map name/floor index or use EVENT_QUEST_POSITION_REQUEST_COMPLETE which is accurate, but only if you have quests and you have to keep in mind that this event occurs for all quests.