Modification to the Communication framework API.

- Simplified the communication API and made it easier to change
  to encrypted connections by not having separate variables to
  define encrypted and unencrypted ports.

- Now, to enable listening without configuring nodes just
  load the frameworks/communication/listen script.

- If encrypted listening is desired set the following:
	redef Communication::listen_encrypted=T;

- Accompanying test updates.

testing/btest/scripts/base/frameworks/logging/remote-types.bro

@@ -48,7 +48,7 @@ event bro_init()
 
 module Test;
 
-@load frameworks/communication/listen-clear
+@load frameworks/communication/listen
 
 event remote_connection_handshake_done(p: event_peer)
 	{

testing/btest/scripts/base/frameworks/logging/remote.bro

@@ -40,7 +40,7 @@ event bro_init()
 
 module Test;
 
-@load frameworks/communication/listen-clear
+@load frameworks/communication/listen
 
 function fail(rec: Log): bool
 	{