2008-02-01 Tatsuhiro Tsujikawa <tujikawa at rednoah dot com>

Added DHT functionality, compatible with mainline.
	DHT is disabled by default. To enable it, give --enable-dht to 
aria2c.
	You may need to specify entry point to DHT network using
	--dht-entry-point. DHT uses UDP port to listen incoming message.
	Use --dht-listen-port to specify port number. Make sure that 
your
	firewall configuration can pass through UDP traffic to the port.
	The routing table is saved in $HOME/.aria2/dht.dat.
	* src/DHT*
	* src/BNode.{h, cc}
	* src/PeerInteractionCommand.cc: enable DHT functionality for a
	particular torrent.
	* src/Data.cc: Rewritten ctor.
	* src/OptionHandlerFactory.cc: Added --enable-dht, 
--dht-listen-port,
	--dht-entry-point.
	* src/DefaultBtInteractive.cc: Send port message if dht is 
enabled.
	* src/RequestGroup.cc: Initialize DHT functionality. When 
download
	ends, remove BtContext from DHTPeerAnnounceStorage.
	* src/BtPortMessage.{h, cc}: Rewritten.
	* src/message.h
	* src/OptionHandlerImpl.cc
	* src/option_processing.cc: Added --enable-dht, 
--dht-listen-port,
	--dht-entry-point.
	* src/Dictionary.{h, cc} (remove): New function.
	* src/prefs.h
	* src/DefaultBtMessageFactory.h
	* src/BtHandshakeMessage.cc
	* src/ActivePeerConnectionCommand.cc
	* src/SocketCore.{h, cc}: Added datagram socket support.
	* src/DefaultBtMessageFactory.cc
	* src/BtSetup.cc: Add BtContext to DHTPeerAnnounceStorage here.
	Create DHT commands.
	* src/BtMessageFactory.h
	* src/PeerMessageUtil.{h, cc}

test/DHTNodeTest.cc

@@ -0,0 +1,26 @@
+#include "DHTNode.h"
+#include "Exception.h"
+#include "Util.h"
+#include <cppunit/extensions/HelperMacros.h>
+
+class DHTNodeTest:public CppUnit::TestFixture {
+
+  CPPUNIT_TEST_SUITE(DHTNodeTest);
+  CPPUNIT_TEST(testGenerateID);
+  CPPUNIT_TEST_SUITE_END();
+public:
+  void setUp() {}
+
+  void tearDown() {}
+
+  void testGenerateID();
+};
+
+
+CPPUNIT_TEST_SUITE_REGISTRATION(DHTNodeTest);
+
+void DHTNodeTest::testGenerateID()
+{
+  DHTNode node;
+  cerr << Util::toHex(node.getID(), DHT_ID_LENGTH) << endl;
+}