Support full URL on pagination links

[hstove]

Reported issue:

When fetching results with over the maximum count of records, radiks-server automatically adds pagination links to the JSON.

However, it appears that it doesn't properly include the host name, according to this screenshot:

This is where that code happens, it appears that the host is not being pulled properly:

https://github.com/blockstack-radiks/radiks-server/blob/master/app/controllers/ModelsController.js#L48