Also delete the lkt.old binary because lkt should works just fine with
retro-compat.

Use a 2 digits output for seconds, even if the number of seconds is less than 10.

LKT: The old command line is now named 'lkt.old' for compat issues with other apps using this command

Don't use the deprecated IDLE event, use the {START,END}_FILE events instead
and thus don't be dependent on some callbacks to get the time. Should also fix
the 'minimal' kara duration issue...

- Don't echo things while the server is running
- Display time in logs

- Vocaloids should be autres -> VOCA now
- Add the VT (for VTuber) for VT karas...

Intercept CTRL+C

See merge request !124

Don't do nothing on SIGUSR{1,2} for the moment. SIGQUIT and SIGILL do
the same thing as SIGINT.

You can double ctrl+c to really kill the server, but you will need to
use the -F option when you relaunch the server.