New version notifier and "autoUpdate" config option to let the app update itself

[f1refa11]

the new version notifier might be like:

A new version of mcsleepingserverstarter has been released!
Version update: v1.7.0 -> v1.9.0
Get the executable here: https://github.com/vincss/mcsleepingserverstarter/releases/tag/v1.9.0

and if the "autoUpdate" config option is true:

A new version of mcsleepingserver found: v1.9.0
Self-updating from v1.7.0...
...
Updated successfully! The changes will apply in the next app restart.

For me, it would be useful to let the app update itself so I don't have to go each time to Github and download a new version.

Also, as i know, Windows doesn't allow replacing the running executable, so as a workaround, the app will download the new version to the directory "sleepingstarter_update", and when the app closes, it will execute a simple shell script which will replace old version with a new one.

[vincss]

Hi, I tough about it, there is a right issue to make the executable "runable" on linux ( chmod +x xxx ), it could work on Windows. Also as there is not that much releases, I don't think it would be very useful.