Add support for pulling signed images from a version 2 registry.
Only official images within the library namespace will be pull from the
new registry and check the build signature.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
renaming this struct to more clearly be session, as that is what it
handles.
Splitting out files for easier readability.
Signed-off-by: Vincent Batts <vbatts@redhat.com>