Refactor setupEntries and export route

Refactor setupEntries

Export route to use middleware like this
```
    var myapp = express();
    myapp.use(stubcell.route);
    var server = myapp.listen(9000);
```

Require merge [stubrec](https://github.com/yosuke-furukawa/stubrec/pull/1)
If use forEach, it complicates return logic

```
var matched = null;
entries.forEach(function(entry){
  // matching
  matched = entry;
});
if (matched) {
  return matched;
}else{
  return null;
}
```

I think it is simple to `for`, don't you?