Add glance register image from http service test case

The new test case have swift to serve a file for downloading without
authentication.

The glance service/client extended with the copy_from attribute.

The rest_client will not argue about content-type issues
when the http response status is 200 or any other non error status.

Change-Id: I2bed0d39f408290b3824a3a3b8afcdd3910ee63b
Merge "Add glance register image from http service test case"