All of the packet handlers are instantiating new Threads, when all that is really needed here are Runnables.

See PacketConfigurationUpdate.java#L36 for example.

They are then just casted up to Runnables further down the line, so them being Threads in the first place is a waste in terms of memory allocation and performance (see Thread.java for the overhead that's happening for every packet at the moment).

Submit a PR.

Done!