[Bleeding] Implemented ProjectileLaunchEvent. Addresses BUKKIT-284

src/main/java/net/minecraft/server/World.java

@@ -897,6 +897,11 @@ public class World implements IBlockAccess {
             if (event.isCancelled()) {
                 return false;
             }
+        } else if (entity.getBukkitEntity() instanceof org.bukkit.entity.Projectile) {
+            // Not all projectiles extend EntityProjectile, so check for Bukkit interface instead
+            if (CraftEventFactory.callProjectileLaunchEvent(entity).isCancelled()) {
+                return false;
+            }
         }
         // CraftBukkit end
 

src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java

@@ -491,4 +491,11 @@ public class CraftEventFactory {
 
         return CraftItemStack.createNMSItemStack(bitem);
     }
+
+    public static ProjectileLaunchEvent callProjectileLaunchEvent(Entity entity) {
+        Projectile bukkitEntity = (Projectile) entity.getBukkitEntity();
+        ProjectileLaunchEvent event = new ProjectileLaunchEvent(bukkitEntity);
+        Bukkit.getPluginManager().callEvent(event);
+        return event;
+    }
 }