[Feature Request] Ability to send prompt/sms/email N seconds/minutes in advance of change

[puterboy]

When a print requires a change in filament or pause it would be nice to have the option to get an email, sms or other notification N seconds/minutes in advance (where N could be zero. This would give the operator time to get to the printer to be ready for such change. I find that minimizing the idle time of pauses and filament changes is not only most efficient but minimizes any cool down due to the pause or filament change (and with pauses, this means less time reheating the tool).

This could start rudimentary by just giving the option to send an arbitrary shell command (ideally with the ability to capture the time left and event description perhaps as a shell variable). Then the user could supply a shell command that triggers an email or sms or whatever....

[eyal0]

Maybe this can be fixed by #40? There will be an API to allow users to get the info out of the system.

So you could write whatever program you want to send SMS or email and then use the API to see when is the right time to send the SMS/email.

This seems better to me than trying to get the plugin to run a shell command because if the shell command takes a long time it's going to mess with the plugin. Like, the plugin could launch too many of them and fall behind and stuff.