implements the get_http_url, get_https_url and url functions according to the openstack and aws providers
refactor: duplicate parsing of the storage_uri, file#url uses service.create_temp_url to be able to pass options now
adds :os_account_meta_temp_url_key to test mock helper
corrects object_tests, also working in mock mode now
Merge pull request #2226 from anynines/hp_provider_temp_urls

Temp url generation interface modification according to the aws and openstack providers