New optional virtual host (vhost) feature for routes.

A straightforward alternative to the existing [subdomain route option](http://compoundjs.com/docs/#routing-subdomain).

In the CompoundJS application `config/route.coffee` file, add the vhost option in the 3rd parameter dictionary:
```
  exports.routes = (map) ->
    map.get "/apples/:id", "fruit#action", {vhost: ".fruit.com"}
    map.get "/carrots/:id", "vegetable#action", {vhost: "vegetables.com"}
```

where the `vhost` value is similar to what you would see in a Nginx `server_name` directive:
 1. Hostnames starting with a period (".") are treated like wildcards.  The first example above matches both "fruit.com" and "www.fruit.com"
 2. Are otherwise are treated as exact matches.  The second example above only matches "vegetables.com".