New RPC works over a Unix socket and assumes synchronous
requests with callService.
A new protocol, 'ServiceProto,' is introduced.
New RPC operates over a Unix socket.
Note the setting: (rpc2 unix "/tmp/hbs2-rpc2.socket").
The default rpc2 socket is located at /tmp/hbs2-rpc2.socket.
In the future, TCP RPC may be introduced, requiring only:
1. Authorization/Authentication
This might be accomplished through another wrapped protocol, for instance.
"Dialog"-associated elements are commented out for now,
as they will likely require their own Unix socket.
Dmitry Zuikov