Don't merge player movements (fixes block breaking issues)

Fixes #1640

Spigot-Server-Patches/0403-Optimize-Small-Entity-Movement.patch

@@ -1,4 +1,4 @@
-From ce3b80309494df7c3a3f9c288d3cfe5d07fd8fb3 Mon Sep 17 00:00:00 2001
+From 57dd32ddf7eb78cbf184e12490e15445dc960f91 Mon Sep 17 00:00:00 2001
 From: Aikar <aikar@aikar.co>
 Date: Thu, 1 Nov 2018 19:45:51 -0400
 Subject: [PATCH] Optimize Small Entity Movement
@@ -130,6 +130,25 @@ index 86488e9709..e6348a2931 100644
      protected void initAttributes() {
          super.initAttributes();
          this.getAttributeMap().b(GenericAttributes.e);
+diff --git a/src/main/java/net/minecraft/server/EntityPlayer.java b/src/main/java/net/minecraft/server/EntityPlayer.java
+index 4490b63258..aa5b58066a 100644
+--- a/src/main/java/net/minecraft/server/EntityPlayer.java
++++ b/src/main/java/net/minecraft/server/EntityPlayer.java
+@@ -1643,6 +1643,14 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
+         this.keepLevel = false;
+     }
+ 
++    // Paper start
++    @Override
++    public boolean shouldMergeMovement(double mergeMin, double d0, double d1, double d2) {
++        // We need precise movement for players
++        return false;
++    }
++    // Paper end
++
+     @Override
+     public CraftPlayer getBukkitEntity() {
+         return (CraftPlayer) super.getBukkitEntity();
 diff --git a/src/main/java/net/minecraft/server/EntitySlime.java b/src/main/java/net/minecraft/server/EntitySlime.java
 index e63f4afa9b..f1266c0ce1 100644
 --- a/src/main/java/net/minecraft/server/EntitySlime.java