IMGAPI-40: '-P' -> '-q' quiet for no-progress meter to avoid '-P' conflict in imgadm in platform
IMGAPI-40: '-P' -> '-q' quiet for no-progress meter to avoid '-P' conflict in imgadm in platform

Also normalize default 'PUBLISHED' output column on the 'list'
command to not have the milliseconds.

joyent/sdc-imgapi-cli,joyent/sdc-imgapi-cli