Add nargs to argparse for image-delete command to
allow muliple (optional) positional image-id arguments.
For example:
image-delete xxx aaa yyy will delete valid images
xxx and yyy and print error message for invalid image
aaa. Also with --verbose you can see some extra text
on delete request for each image.
Fixes bug1056498.
Change-Id: I6e804700ed24d16f90ec92569c0893cad4aaa26f
Sulochan Acharya
8b2c227f27