changed Game.level to Game.dungeon_level
changed all Object.level references to Object.xplevel
forgot to fix one level -> xplevel
modified from_dungeon_level to take a level number.  then had to modify some of the calls to it to pass the level name and not the Game object
updated print statement to display Game.dungeon_level
fixed entities.move_away to only work when the target and user are on the same floor.  This may be masking an underlying problem
updated xp system so that each entity accumulates XP
fixed from_dungeon_level to work correctly now
added entities.entity_sees() function for each checks on if an entity can see another entity. If so, returns True
needed to help clean up panel.  updated Fighter.attack to only show messages if the user can see the attacker or defender.
same as last commit. added entity_sees (last commit was first attempt with playersees)