[Auto] Updated Upstream (CraftBukkit)

Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

CraftBukkit Changes:
68588dac SPIGOT-4405: Chunk generation problem

Spigot-Server-Patches/Fix-Sending-Chunks-to-Client.patch

@@ -14,7 +14,7 @@ This fix always sends chunks to the client, and simply updates
 the client anytime post processing is triggered with the new chunk data.
 
 diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
-index 895eb60854..350479dc68 100644
+index 83df52f30..0b0a5424e 100644
 --- a/src/main/java/net/minecraft/server/Chunk.java
 +++ b/src/main/java/net/minecraft/server/Chunk.java
 @@ -0,0 +0,0 @@ public class Chunk implements IChunkAccess {
@@ -27,7 +27,7 @@ index 895eb60854..350479dc68 100644
  
      public boolean v() {
 @@ -0,0 +0,0 @@ public class Chunk implements IChunkAccess {
-             com.google.common.base.Preconditions.checkState(this.h.isEmpty(), "Pending tiles not empty"); // CraftBukkit
+             this.h.clear();
              this.a(ChunkStatus.POSTPROCESSED);
              this.m.a(this);
 +            // Paper start - resend chunk after post process
@@ -41,7 +41,7 @@ index 895eb60854..350479dc68 100644
      }
  
 diff --git a/src/main/java/net/minecraft/server/PlayerChunk.java b/src/main/java/net/minecraft/server/PlayerChunk.java
-index 04ad94e171..748d5f28e5 100644
+index 04ad94e17..748d5f28e 100644
 --- a/src/main/java/net/minecraft/server/PlayerChunk.java
 +++ b/src/main/java/net/minecraft/server/PlayerChunk.java
 @@ -0,0 +0,0 @@ public class PlayerChunk {