[enh] paging support for soundcloud

guest_client_id = 'b45b1aa10f1ac2941910a7f0d10f8e28'

url = 'https://api.soundcloud.com/'

search_url = url + 'search?{query}&facet=model&limit=20&offset=0&linked_partitioning=1&client_id='+guest_client_id  # noqa

search_url = url + 'search?{query}&facet=model&limit=20&offset={offset}&linked_partitioning=1&client_id='+guest_client_id  # noqa

paging = True

def request(query, params):

    global search_url

    params['url'] = search_url.format(query=urlencode({'q': query}))

    offset = (params['pageno'] - 1) * 20

    params['url'] = search_url.format(query=urlencode({'q': query}),

                                      offset=offset)

    return params