Change daemon directory

I put my source files in `/src` similar to many other projects and since my `index.js` in under `/src` the output daemon folder will be created as `/src/daemon`. I need to specify the output daemon folder in node-windows config like `daemonDir`. If you add this option it's very good.

Meanwhile, I solved my problem as follows:

I changed `node_modules\node-windows\lib\daemon.js` file at line 258 from:
```
_directory: {
enumerable: false,
writable: true,
configurable: false,
value: config.script !== null ? path.dirname(config.script) : null
},
```
to
```
_directory: {
enumerable: false,
writable: true,
configurable: false,
value: config.daemonDir !== null ? path.dirname(config.daemonDir) : null
},
```

And specify `daemonDir` at config:
```
var svc = new Service({
name: "My Server",
description: "My Server",
script: "src/index.js",
daemonDir: "./",
});
```

Start in lib/daemon.js around line 258, where the daemon directory is derived from config.script. Review the proposed daemonDir configuration shown in the issue and verify how the daemon output path is used. Done means the service accepts daemonDir and creates or uses the daemon folder at that configured location.

Written by the indexing model from the issue text.