wrapper.js: reset attempts and log exit code

currently, the following lines are dead code as `child` is `null` when `monitor` is called
https://github.com/coreybutler/node-windows/blob/accfbd0528ad5148cb6283e5d8f2b407f890dfbc/lib/wrapper.js#L120-L125

This suggests that `monitor` may not be used as originally intended, and it means that even successful restarts suffer from accumulated delays, keeping the child offline without reason.

Given the ressource limitations on this project, I would suggest a minor fix: after the `fork` (https://github.com/coreybutler/node-windows/blob/accfbd0528ad5148cb6283e5d8f2b407f890dfbc/lib/wrapper.js#L162) add
```
if (child && child.pid) {
// reset attempts and wait time
attempts = 0;
wait = argv.w * 1000;
}
```

Also, please don't hide the child's exit code - it is sometimes the only available clue to what went wrong.

https://github.com/coreybutler/node-windows/blob/accfbd0528ad5148cb6283e5d8f2b407f890dfbc/lib/wrapper.js#L165-L166

`log.warn(argv.f+' stopped running with code: '+code.toString(16));`