Fixed connection to 1.7 Thermos servers

Readd changes from #157 and #261
Changed packet constructors type from Array to Map to allow negative packet ids (can occur in CoFH mods for example)

protocol/src/main/java/net/md_5/bungee/protocol/Protocol.java

@@ -471,7 +471,7 @@ private static class ProtocolData
         private final int protocolVersion;
         private final TObjectIntMap<Class<? extends DefinedPacket>> packetMap = new TObjectIntHashMap<>( MAX_PACKET_ID );
         @SuppressWarnings("unchecked")
-        private final Supplier<? extends DefinedPacket>[] packetConstructors = new Supplier[ MAX_PACKET_ID ];
+        private final TIntObjectMap<Supplier<? extends DefinedPacket>> packetConstructors = new TIntObjectHashMap<>( MAX_PACKET_ID );
     }
 
     @Data
@@ -530,7 +530,7 @@ public final DefinedPacket createPacket(int id, int version)
                 throw new BadPacketException( "Packet with id " + id + " outside of range" );
             }
 
-            Supplier<? extends DefinedPacket> constructor = protocolData.packetConstructors[id];
+            Supplier<? extends DefinedPacket> constructor = protocolData.packetConstructors.get(id);
             return ( constructor == null ) ? null : constructor.get();
         }
 
@@ -561,7 +561,7 @@ private void registerPacket(Class<? extends DefinedPacket> packetClass, Supplier
 
                 ProtocolData data = protocols.get( protocol );
                 data.packetMap.put( packetClass, mapping.packetID );
-                data.packetConstructors[mapping.packetID] = constructor;
+                data.packetConstructors.put(mapping.packetID, constructor);
             }
         }