Added script for building Base Docker CRUX images

Docker-DCO-1.1-Signed-off-by: James Mills <prologic@shortcircuit.net.au> (github: therealprologic)
Merge pull request #3720 from therealprologic/master

Add script for building CRUX base images
update REMOTE_TODO.md

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #3738 from vieux/update_todo

update REMOTE_TODO.md