Added SlimeSplit event. Thanks garbagemule!

The SlimeSplit event is fired when a Slime attempts to split upon death.
The event may be cancelled, and the amount of smaller slimes may be
customized.

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

@@ -0,0 +1,157 @@
+package net.minecraft.server;
+
+public class EntitySlime extends EntityLiving implements IMonster {
+
+    public float a;
+    public float b;
+    private int size = 0;
+
+    public EntitySlime(World world) {
+        super(world);
+        this.texture = "/mob/slime.png";
+        int i = 1 << this.random.nextInt(3);
+
+        this.height = 0.0F;
+        this.size = this.random.nextInt(20) + 10;
+        this.setSize(i);
+        this.ax = i;
+    }
+
+    protected void b() {
+        super.b();
+        this.datawatcher.a(16, new Byte((byte) 1));
+    }
+
+    public void setSize(int i) {
+        this.datawatcher.watch(16, new Byte((byte) i));
+        this.b(0.6F * (float) i, 0.6F * (float) i);
+        this.health = i * i;
+        this.setPosition(this.locX, this.locY, this.locZ);
+    }
+
+    public int getSize() {
+        return this.datawatcher.getByte(16);
+    }
+
+    public void b(NBTTagCompound nbttagcompound) {
+        super.b(nbttagcompound);
+        nbttagcompound.a("Size", this.getSize() - 1);
+    }
+
+    public void a(NBTTagCompound nbttagcompound) {
+        super.a(nbttagcompound);
+        this.setSize(nbttagcompound.e("Size") + 1);
+    }
+
+    public void s_() {
+        this.b = this.a;
+        boolean flag = this.onGround;
+
+        super.s_();
+        if (this.onGround && !flag) {
+            int i = this.getSize();
+
+            for (int j = 0; j < i * 8; ++j) {
+                float f = this.random.nextFloat() * 3.1415927F * 2.0F;
+                float f1 = this.random.nextFloat() * 0.5F + 0.5F;
+                float f2 = MathHelper.sin(f) * (float) i * 0.5F * f1;
+                float f3 = MathHelper.cos(f) * (float) i * 0.5F * f1;
+
+                this.world.a("slime", this.locX + (double) f2, this.boundingBox.b, this.locZ + (double) f3, 0.0D, 0.0D, 0.0D);
+            }
+
+            if (i > 2) {
+                this.world.makeSound(this, "mob.slime", this.l(), ((this.random.nextFloat() - this.random.nextFloat()) * 0.2F + 1.0F) / 0.8F);
+            }
+
+            this.a = -0.5F;
+        }
+
+        this.a *= 0.6F;
+    }
+
+    protected void c_() {
+        this.ad();
+        EntityHuman entityhuman = this.world.findNearbyPlayer(this, 16.0D);
+
+        if (entityhuman != null) {
+            this.a(entityhuman, 10.0F, 20.0F);
+        }
+
+        if (this.onGround && this.size-- <= 0) {
+            this.size = this.random.nextInt(20) + 10;
+            if (entityhuman != null) {
+                this.size /= 3;
+            }
+
+            this.aS = true;
+            if (this.getSize() > 1) {
+                this.world.makeSound(this, "mob.slime", this.l(), ((this.random.nextFloat() - this.random.nextFloat()) * 0.2F + 1.0F) * 0.8F);
+            }
+
+            this.a = 1.0F;
+            this.aP = 1.0F - this.random.nextFloat() * 2.0F;
+            this.aQ = (float) (1 * this.getSize());
+        } else {
+            this.aS = false;
+            if (this.onGround) {
+                this.aP = this.aQ = 0.0F;
+            }
+        }
+    }
+
+    public void die() {
+        int i = this.getSize();
+
+        if (!this.world.isStatic && i > 1 && this.health == 0) {
+            // CraftBukkit start
+            org.bukkit.event.entity.SlimeSplitEvent event = new org.bukkit.event.entity.SlimeSplitEvent(this.getBukkitEntity(), 4);
+            this.world.getServer().getPluginManager().callEvent(event);
+
+            if (!event.isCancelled() && event.getCount() > 0) {
+                for (int j = 0; j < event.getCount(); ++j) {
+                    float f = ((float) (j % 2) - 0.5F) * (float) i / 4.0F;
+                    float f1 = ((float) (j / 2) - 0.5F) * (float) i / 4.0F;
+                    EntitySlime entityslime = new EntitySlime(this.world);
+
+                    entityslime.setSize(i / 2);
+                    entityslime.setPositionRotation(this.locX + (double) f, this.locY + 0.5D, this.locZ + (double) f1, this.random.nextFloat() * 360.0F, 0.0F);
+                    this.world.addEntity(entityslime);
+                }
+            }
+            // CraftBukkit end
+        }
+
+        super.die();
+    }
+
+    public void a_(EntityHuman entityhuman) {
+        int i = this.getSize();
+
+        if (i > 1 && this.f(entityhuman) && (double) this.g(entityhuman) < 0.6D * (double) i && entityhuman.damageEntity(DamageSource.mobAttack(this), i)) {
+            this.world.makeSound(this, "mob.slimeattack", 1.0F, (this.random.nextFloat() - this.random.nextFloat()) * 0.2F + 1.0F);
+        }
+    }
+
+    protected String i() {
+        return "mob.slime";
+    }
+
+    protected String j() {
+        return "mob.slime";
+    }
+
+    protected int k() {
+        return this.getSize() == 1 ? Item.SLIME_BALL.id : 0;
+    }
+
+    public boolean d() {
+        Chunk chunk = this.world.getChunkAtWorldCoords(MathHelper.floor(this.locX), MathHelper.floor(this.locZ));
+
+        return (this.getSize() == 1 || this.world.difficulty > 0) && this.random.nextInt(10) == 0 && chunk.a(987234911L).nextInt(10) == 0 && this.locY < 16.0D;
+    }
+
+    protected float l() {
+        return 0.6F;
+    }
+}