Break dataBundle into two pieces: inputBundle, which contains data that
is specific to the pki backend, and creationBundle, which is a more
generic bundle of validated inputs given to certificate creation/signing routines.
Move functions that only take creationBundle to certutil and make them public.
* Disallow adding CA's serial to revocation list
* Allow disabling revocation list generation. This returns an empty (but
signed) list, but does not affect tracking of revocations so turning it
back on will populate the list properly.
* Start work on passing context to backends
* More work on passing context
* Unindent logical system
* Unindent token store
* Unindent passthrough
* Unindent cubbyhole
* Fix tests
* use requestContext in rollback and expiration managers
A buffer is used to ensure that we only remove certificates that are
both expired and for which the buffer has past. Options allow removal
from revoked/ and/or certs/.