Release Candidate 2: Gold, Damage indicators, and Polish

Changes since RC1:

• Weapons now play a sound on hit
• Flails and spears display sprites where they could hit, which greatly helps in explaining their area of effect to new players
• Fixed a nasty bug that had enemies sometimes end up on top of the player, dealing constant damage
• Treasure amounts greatly increased on lower floors
• All enemies award gold when defeated, according to their type and difficulty