Removed uniqueId setting from within ObjectGroup clone. Added uniqueId to the Map::adoptLayer instead.
Setting the uniqueId of the MapObject and the nextUid of the Map to -1 by default . Can now use this to check if the uniqueId's have been set and set if required in ObjectGroup::addObject, ObjectGroup::insertObject and Map::adoptLayer
Tidy up unused includes and reverted pythonbind