added Level.lua, added folder for challenges, implemented levels
use direct variables instead of methods, moved code into functions.lua
fixed variables who weren't local, challenges be repeatable, modified/fixed default challenges, use other color in list if challenge is repeable, added check command for challenges, fixed arguments of method ParseStringToItems
corrected a few comments, adjusted Easy.ini, added example challenges to Medium.ini, fixed error in check if challenge is not repeatable