Add support to Bro for connecting with peers over IPv6.

- Communication::listen_ipv6 needs to be redef'd to true in order
  for IPv6 listening sockets to be opened.

- Added Communication::listen_retry option as an interval at which
  to retry binding to socket addresses that were already in use.

- Added some explicit baselines to check in the istate.events
  and istate.events-ssl tests -- the SSL test was incorrectly
  passing because it compared two empty files.  (The files being
  empty because "http/base" was given as an argument to Bro which
  it couldn't handle because that script doesn't exist anymore).

src/IPAddr.h

@@ -188,11 +188,16 @@ public:
 	 * IPv4 to IPv6 address mapping to return a full 16 bytes.
 	 *
 	 * @param bytes The pointer to a memory location in which the
-	 * raw bytes of the address are to be copied in network byte-order.
+	 * raw bytes of the address are to be copied.
+	 *
+	 * @param order The byte-order in which the returned raw bytes are copied.
+	 * The default is network order.
 	 */
-	void CopyIPv6(uint32_t* bytes) const
+	void CopyIPv6(uint32_t* bytes, ByteOrder order = Network) const
 		{
 		memcpy(bytes, in6.s6_addr, sizeof(in6.s6_addr));
+		if ( order == Host )
+			for ( unsigned int i = 0; i < 4; ++i ) bytes[i] = ntohl(bytes[i]);
 		}
 
 	/**
@@ -280,6 +285,19 @@ public:
 	 */
 	string AsString() const;
 
+	/**
+	 * Returns a string representation of the address suitable for inclusion
+	 * in an URI.  For IPv4 addresses, this is the same as AsString(), but
+	 * IPv6 addresses are encased in square brackets.
+	 */
+	string AsURIString() const
+		{
+		if ( GetFamily() == IPv4 )
+			return AsString();
+		else
+			return string("[") + AsString() + "]";
+		}
+
 	/**
 	 * Returns a host-order, plain hex string representation of the address.
 	 */