Add SSL support to utils.generate_glance_url().
Add SSL support to utils.generate_glance_url().

Since glance now supports SSL, we need to take
this into consideration when generating the URL.
Also updates and adds a test.

A new config option 'glance_protocol' was added
that defaults to 'http' since that's what the
glance options, '*_client_protocol', default to.
Set to 'https' for SSL.

Change-Id: Id231a1fd4c4d8e221ae0cf6541181e5572dff02b

n0ano/ganttclient