Turret System Overhaul

The amount of adjustments here are too numerous to list, but the main changes are the following:

• Turret upgrades are no longer lone entities, but stack onto one of your two turret slots instead
• Turrets now require gears for purchasing rather than coins
• Gears are acquired by defending towers that spawn near a hero character once every minute.
• Mobs now have more HP to account, requiring players to maximize their particular hero's upgrade routes in order to maintain character-specific DPS
• Max HP scaling increased for all characters
• Damage scaling increased for all mobs
• Revives have been migrated from buyables to a 1 minute timer in game
• The underlying code has been shifted from single player to peer-based multiplayer. Official, functional multiplayer is still in development, however.