eldritch horrors
d8e2f53d07
ca derivations are what we're really after, but dynamic derivations must also go because they depend on ca derivations. we can't easily implement dynamic derivations any other way, so we remove them too. impure derivations build on the content-addressed infrastructure in ways we cannot easily detangle, so they too must go for time being. see #815 Change-Id: If61371736dfd89cc71a1b2ae5a005757c3cb9484