Cannons

Written Tutorial: https://dev.bukkit.org/projects/cannons/pages/tutorial

Video Tutorial: https://www.youtube.com/watch?v=g-boSAAQFB0

Our changes:

• Only iron cannons and mortars are available. This is a balance decision.
• No monetary cost to build cannons.
• Cobblestone projectiles are not incendiary.
• Diamond projectiles are currently disabled.
• Hot cannons will cause damage if touched.