This change fixes a bug that causes PlainObjectCodec to
lose additional messages from stream. json.Decoder has
an internal buffer that reads more than one message, but
is discarded after every use. Now PlainObjectCodec reuses
encoder and decoder within a buffered stream, however
using it directly in your code retains the old, incorrect
behaviour.
A user should now use plainObjectStream if he needs
plain JSON-RPC 2.0 stream without headers.
`NewPlainObjectStream` method has been added for this reason.
Running various applications that use jsonrpc2 with the Go race detector shows that there is a race condition where `WriteObject` can be called from concurrent goroutines (e.g., 1 sending a request, 1 writing a response).
simplify API by using interface{}, rename from transport -> stream
add WebSocket transport in websocket subpackage
do not buffer in ReadObject, rename GetObjectReader/ReadObject -> NextObjectReader
use xtest (jsonrpc2_test) package to allow us to test subpackages that depend on us (in a future change)
factor out vscode-specific transport code and allow pluggable transports
remove Server (unused) and Serve (unnecessary):
The Serve func had nothing specific to JSON-RPC; it was just a loop
around (net.Listener).Accept. It added no value.
