Sort of format for CursiveLogWriter

[inferrna]

Hi. Now it is possible to write like this, so it became kinda flexible.

    Logger::try_with_env_or_str("info")
        .expect("Could not create Logger from environment :(")
        .filter(Box::new(MineOnly))
        .format(my_detailed_format)
        .format_for_writer(my_detailed_format)
        .log_to_file_and_writer(
            flexi_logger::FileSpec::default()
                .directory("logs")
                .suppress_timestamp(),
            cursive_flexi_logger_view::cursive_flexi_logger(&siv)
                .with_format(vec![DATETIME, LEVEL, FileLine, MESSAGE]) //These two lines are optional
                .with_time_format("%R") //without it all intended to work like before
        )
        .start()
        .expect("failed to initialize logger!");