STY: Use references in for loops and a lot of whitespaces

include/caosdb/authentication.h

include/caosdb/configuration.h

include/caosdb/connection.h

include/caosdb/data_type.h

include/caosdb/entity.h

include/caosdb/exceptions.h

include/caosdb/file_transmission/download_request_handler.h

...e/caosdb/file_transmission/register_file_upload_handler.h

include/caosdb/file_transmission/upload_request_handler.h

include/caosdb/info.h

include/caosdb/logging.h

include/caosdb/message_code.h

include/caosdb/protobuf_helper.h

include/caosdb/transaction.h

include/caosdb/transaction_handler.h

include/caosdb/transaction_status.h

include/caosdb/unary_rpc_handler.h

include/caosdb/utility.h

include/caosdb/value.h

include/ccaosdb.h