RDFObjects/Pho integration.

Interact with Talis Platform stores using RDFObjects objects.

Usage:

>> require 'rdf_objects/pho'
>> store = RDFObject::Store.new('http://api.talis.com/store/storename', 'username', 'password')
>> response = store.describe('http://example.org/1')

Responses have two new attributes:  collection and resource.  Collection will always be set, resource will only be set when applicable (describe, search, etc.)

You can also pass RDFObject::Resource, RDFObject::BlankNode and RDFObject::Collection objects to Store#store_object, and Store#augment.  You can pass an RDFObject::ChangeSet to Store#submit_changeset.