Added more core systems + 2nd boss

Added a new boss to my game Castle of the Necromancer. This evil goblin mage spawns fireballs that shoot towards you! You'll have to dodge them while darting in and attacking where possible.

A little less exciting, but I also worked on a number of core systems to the game -- the ability to equip items, sleep, and purchase things from shopkeepers. Just have to finish the last 10ish levels before Wednesday!