Test with Meteor running on any port

The Meteor Router test suite will now run on ports other than 3000.
To see this in action, invoke `mrt` with a non-standard port:

``` sh
$ mrt --port 3030
```

This work replaces all hand-constructed test paths with [`Meteor.absoluteUrl()`](http://docs.meteor.com/#meteor_absoluteurl).

Also removed trailing spaces and added semicolons per the [Meteor Style Guide](https://github.com/meteor/meteor/wiki/Meteor-Style-Guide).