Initial support for taggable dependencies

Introduce a new --no-use-released-parent option to `build-docker-image`
that allows specifying whether the parent image uses the same tag as
the one that's currently build or the release tag.

Default is to use the release tag for parent image, however
`build-all-docker-images` script forces it to be the current tag.

Change to Dockerfile is coming next.

Change-Id: Ief11c9abb722c181ca85f38ee11800dbf4332a5f