[Bleeding] Added ProjectileLaunchEvent. Addresses BUKKIT-284

By: Celtic Minstrel <celtic.minstrel.ca@some.place>

paper-api/src/main/java/org/bukkit/event/entity/ProjectileLaunchEvent.java

@@ -0,0 +1,40 @@
+package org.bukkit.event.entity;
+
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.Projectile;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+
+/**
+ * Called when a projectile is launched.
+ */
+public class ProjectileLaunchEvent extends EntityEvent implements Cancellable {
+    private static final HandlerList handlers = new HandlerList();
+    private boolean cancelled;
+
+    public ProjectileLaunchEvent(Entity what) {
+        super(what);
+    }
+
+    public boolean isCancelled() {
+        return cancelled;
+    }
+
+    public void setCancelled(boolean cancel) {
+        cancelled = cancel;
+    }
+
+    @Override
+    public Projectile getEntity() {
+        return (Projectile) entity;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}