Reserve at server startup some guods follow last used in static DB spawns guid
for creatures/gameobjects for use in .npc add/.gobject add commands.
This allow safe select guids not used in all map copies. Guids for temporary spawns
used from range frollow after reserved guids range.
This also let select new static spawns guids (added in game chat command) near to already used static guids.
So it let avoid gaps in static guids lists.
Amount reserved guids set in new GuidReserveSize.* config options.
