Removed over-agressive catching of errors when loading Less and Stylus

I'm using hapi-meal for the first time and am setting up a new project. During that process I ran into the problem where the node.js process exits with just the following log message:

	TypeError: Cannot read property 'length' of undefined

It took more than an hour to figure out that it's caused by hapi-meal if the assets settings are incomplete:

```javascript
assets: {
	stylus: {
		path: 'assets/styles'
	}
}
```

`files` was missing in `stylus` and caused the error above.

Since hapi-meal caught all errors when setting up Less or Stylus and thus did not provide a stack trace it was difficult  to debug.

Errors during the application setup should not be caught by a catch-all clause.