v0.16 Fire and Golem Factories

added fires that start when you shoot an enemy with cross - fire weapon

enemies catch on fire when they walk into fires

Gems and items fade away after 10 seconds

Added Golem Factory

Added sound for Golem Factory

Added on/off switch for Golem Factory

Enemies can drop more rare gems that give more xp

Reduced damage multiplier for upgrades

Added Audio busses for SFX and Music