update dhtnet and cleanup fileutils

contrib/src/dhtnet/package.json

contrib/src/dhtnet/rules.mak

src/account.cpp

src/archiver.cpp

src/connectivity/security/tlsvalidator.cpp

src/data_transfer.cpp

src/fileutils.cpp

src/fileutils.h

src/im/message_engine.cpp

src/jamidht/archive_account_manager.cpp

src/jamidht/contact_list.cpp

src/jamidht/conversation.cpp

src/jamidht/conversation_module.cpp

src/jamidht/conversationrepository.cpp

src/jamidht/jamiaccount.cpp

src/jamidht/jamiaccount.h

src/jamidht/namedirectory.cpp

src/logger.cpp

src/logger.h

src/manager.cpp