When the XP table is overriden in a level file, it should be written by the editor when the level is saved
fixes #347
When saving the skirmish test small map, sometimes, wizard and aventurer XP table was written even if not overriden
Merge pull request #351 from hwoarangmy/development

When the XP table is overriden in a level file, it should be written by the editor when the level is saved