Function kwait::non_sliding_until

pub fn non_sliding_until<F>(f: F, period: Duration, stop_ch: Receiver<bool>) where
    F: Fn(), 

non_sliding_until loops until stop channel is closed, running f every period.

non_sliding_until is syntactic sugar on top of jitter_until with zero jitter factor, with sliding = false (meaning the timer for period starts at the same time as the function starts).