Add 1.9.1 support.

By: md_5 <git@md-5.net>

paper-server/nms-patches/PacketEncoder.patch

@@ -0,0 +1,27 @@
+--- a/net/minecraft/server/PacketEncoder.java
++++ b/net/minecraft/server/PacketEncoder.java
+@@ -14,6 +14,7 @@
+     private static final Logger a = LogManager.getLogger();
+     private static final Marker b = MarkerManager.getMarker("PACKET_SENT", NetworkManager.b);
+     private final EnumProtocolDirection c;
++    int version; // CraftBukkit
+ 
+     public PacketEncoder(EnumProtocolDirection enumprotocoldirection) {
+         this.c = enumprotocoldirection;
+@@ -30,6 +31,7 @@
+             throw new IOException("Can\'t serialize unregistered packet");
+         } else {
+             PacketDataSerializer packetdataserializer = new PacketDataSerializer(bytebuf);
++            packetdataserializer.version = version; // CraftBukkit
+ 
+             packetdataserializer.b(integer.intValue());
+ 
+@@ -42,7 +44,7 @@
+         }
+     }
+ 
+-    protected void encode(ChannelHandlerContext channelhandlercontext, Object object, ByteBuf bytebuf) throws Exception {
++    protected void encode(ChannelHandlerContext channelhandlercontext, Packet object, ByteBuf bytebuf) throws Exception {
+         this.a(channelhandlercontext, (Packet) object, bytebuf);
+     }
+ }