When decoding STOMP messages unread portions of a given input ByteBuf
must be kept until more input is received and the next complete STOMP
frame can be parsed.
In Reactor Net 2.x this was handled for us through the "remainder"
field in NettyChannelHandlerBridge. The Reactor Netty 0.6 upgrade
however applied only a simple map operator on the input ByteBuf
after which the buffer is relased.
This commit replaces the use of a simple map operator for decoding
and installs a ByteToMessageDecoder in the Netty channel pipeline
which has a built-in ability to preserve and merge unread input into
subsequent input buffers.
ea274ebc0a