Revert "digraph always computed ready to write out to a file"

This reverts commit 69568048e1dd1bfd544a9b5bdea8be50786a26dc.
Revert "make simplified"

This reverts commit 04f4b123cb5b0a9f96e6ece34ec134c64c98331c.
Revert "shutit dist base"

This reverts commit 004c4d100424fe73dd11896a9d1b8589455be472.
container replaced with target in preparation for more general handling of multiple environments