Update: shotgun, rocket launcher, freezing barrel!

What's new:

• New weapons:
  • Shotgun: fires a hail of projectiles (4 rounds, 0.8 second cooldown) which kill or destroy everything pistol bullets kill or destroy.
  • Rocket launcher: fires an accelerating rocket (3 rounds, 1.5 second cooldown) that explodes on impact killing / destroying everything in its radius.
• New placeable: liquid nitrogen barrel. When blown up, it freezes nearby players and NPCs for 5 seconds.
• Added weapon fire button for touch controls.