Fix a bug Arthur reported. Some critical Peer structures are not protected

against races caused by concurrent reading from and writing to the SSL
connection and access to Peer variables like mDetaching, mSendingPacket, and
so on.

src/cpp/ripple/Peer.h

@@ -58,6 +58,7 @@ private:
 
 protected:
 
+	boost::recursive_mutex ioMutex;
 	std::vector<uint8_t> mReadbuf;
 	std::list<PackedMessage::pointer> mSendQ;
 	PackedMessage::pointer mSendingPacket;