conserver: add advanced serial console package

Conserver is an application that allows multiple users to use
serial consoles at the same time, with logging.  It has a client-
server design which makes it easy to manage a distributed set
of serial consoles.  Logging makes post-crash analyses easier.

Signed-off-by: Bjørn Mork <bjorn@mork.no>

net/conserver/files/console.cf

@@ -0,0 +1,4 @@
+config * {
+	master	localhost;
+	port	3109;
+}