Politely ask a program to quit, and then enforce it to. Cross-platform.
processis an object returned by any function of the library child_process.
callbackis an optional function which will get called after process ended.
It will be called as
callback( signal_or_error_received, return_code ).
optionsis an object with any of the following properties :
timeout: delay (in seconds) before killing process if it didn't react to initial request to quit (defaults to 5).