Intermediary level added in between floors; You can now trade coins for arrow power-up, speed boost, hearts and arrows.

- added an intermediary one room dungeon to the ToNextLevelState
- created Entity "Murk" as an npc  who remains in this GameState to potentially trade for coins
- added textbox and simple dialogue
- the power charged arrow must now be purchased; a speed boost, 10 arrows, and a heart can also be purchased.
- new Sprite art integrated for NPC
- also added a short dying scenario; when hero dies he freezes, spins, & everything flashes (similar to the box2d debug mode)
Hmmm.. these variables are static! I feel like these powerups should be stored in the instances of the heroes, and not the static class for this gamestate. When the game resets, we have to manually disable all of these booleans!