NPC Dialogue fixed

NPC dialogue works. Currently has serious issues with "magic numbers"
(as does my inventory/building menus) that will have to be resolved. All
HUD elements need to be tied to Screen width/height in the future so
stuff doesn't look wonky. Currently only displays properly on Maximize
On Play option. Functions properly. Also, deleted NPC_Dialogue object
since it was unnecessary and attached NPC_Dialogue script to NPC object.