This plugin implements JSON-RPC protocol version 2.0
(http://www.jsonrpc.org/specification) operating over TCP/Netstrings.
Each request and response is of form <size>:<request or response> where
<size> tells the number of bytes in <request or response>.

Configuration file jsonrpc.conf can contain parameters jsonrpc_port
(default 7080) and server_threads (default 5).
