Call EntityDamageEvent on ItemFrame item removal. Fixes BUKKIT-5020

Calling this event allows plugins to react to the situation by simply
handling a normal damage event, possibly using existing code to
handle other entity damage.

Pulled from PR #1279

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

@@ -23,6 +23,11 @@ public class EntityItemFrame extends EntityHanging {
             return false;
         } else if (this.getItem() != null) {
             if (!this.world.isStatic) {
+                // CraftBukkit start
+                if (org.bukkit.craftbukkit.event.CraftEventFactory.handleEntityDamageEvent(this, damagesource, f).isCancelled() || this.dead) {
+                    return false;
+                }
+                // CraftBukkit end
                 this.b(damagesource.getEntity(), false);
                 this.setItem((ItemStack) null);
             }