Rewritten a portion of bittorrent implementation:
* src/BtMessageValidator.h: New class.
* src/BtBitfieldMessageValidator.h: New class.
* src/BtHandshakeMessageValidator.h: New class.
* src/BtRequestMessageValidator.h: New class.
* src/BtSuggestPieceMessageValidator.h: New class.
* src/BtAllowedFastMessageValidator.h: New class.
* src/BtRejectMessageValidator.h: New class.
* src/BtCancelMessageValidator.h: New class.
* src/BtPieceMessageValidator.h: New class.
* src/BtHaveMessageValidator.h: New class.
* src/BtEventListener.h: New class.
* src/AbstractBtEventListener.h: New class.
* src/BtEvent.h: New class.
* src/BtChokingEvent.h: New class.
* src/BtChokedEvent.h: New class.
* src/BtCancelSendingPieceEvent.h: New class.
* src/BtAbortOutstandingRequestEvent.h: New class.
* src/Randomizer.h: New class.
* src/SimpleRandomizer.h: New class.
* src/BtMessage.h: New class.
* src/AbstractBtMessage.h: New class.
* src/SimpleBtMessage.h: New class.
* src/BtHaveMessage.h: New class.
* src/BtInterestedMessage.h: New class.
* src/BtAllowedFastMessage.h: New class.
* src/BtUnchokeMessage.h: New class.
* src/BtCancelMessage.h: New class.
* src/BtNotInterestedMessage.h: New class.
* src/BtChokeMessage.h: New class.
* src/BtHaveNoneMessage.h: New class.
* src/BtHandshakeMessage.h: New class.
* src/BtSuggestPieceMessage.h: New class.
* src/BtHaveMessage.h: New class.
* src/BtPieceMessage.h: New class.
* src/BtHaveAllMessage.h: New class.
* src/BtKeepAliveMessage.h: New class.
* src/BtPortMessage.h: New class.
* src/BtRejectMessage.h: New class.
* src/BtBitfieldMessage.h: New class.
* src/BtRequestMessage.h: New class.
* src/DefaultBtRequestFactory.h: New class.
* src/DefaultBtMessageReceiver.h: New class.
* src/BtInteractive.h: New class.
* src/BtMessageDispatcher.h: New class.
* src/DefaultBtMessageDispatcher.h: New class.
* src/DefaultBtInteractive.h: New class.
* src/BitfieldManFactory.h: New class.
* src/HandleRegistry.h: New class.
* src/BtMessageFactory.h: New class.
* src/BtMessageReceiver.h: New class.
* src/DefaultBtMessageFactory.h: New class.
* src/PeerObject.h: New class.
* src/BtRequestFactory.h: New class.