terminal: extract RPC proxy

To make the purpose and the flow of the RPC proxy more easy to
understand, it is extracted into its own struct and cleaned up.

Author: guggero

config.go

@@ -28,6 +28,8 @@ const (
 	defaultHTTPSListen = "127.0.0.1:8443"
 
 	uiPasswordMinLength = 8
+
+	defaultLndMacaroon = "admin.macaroon"
 )
 
 var (

log.go

@@ -67,6 +67,9 @@ func SetupLoggers(root *build.RotatingLogWriter) {
 	lnd.AddSubLogger(root, "LNDC", lndclient.UseLogger)
 	lnd.AddSubLogger(root, "STORE", loopdb.UseLogger)
 	lnd.AddSubLogger(root, lsat.Subsystem, lsat.UseLogger)
+
+	// Setup the gRPC loggers too.
+	grpclog.SetLoggerV2(NewGrpcLogLogger(root, GrpcLogSubsystem))
 }
 
 // NewGrpcLogLogger creates a new grpclog compatible logger and attaches it as