in #276 we introduced an argument -h or -hotkey that when there is already another instance running then send hotkey instead of killing the other instance

in #305 we made this option default true and introduced an argument -r that when there is already another instance running then kill the other one (for the old behavior)

but if application is hanging due to a bug it is important that we default restart (kill other instances) instead of sending hotkey to other instance

and also let's do as an checkbox in options instead as argument