* add db interface and methods, add sa metainfo endpoints and svc
* add bucket metainfo svc funcs
* add sadb bucekts
* bucket list gets all buckets
* filter buckets list on macaroon restrictions
* update pb cipher suite to be enum
* add conversion funcs
* updates per comments
* bucket settings should say default
* add direction to list buckets, add tests
* fix test bucket names
* lint err
* only support forward direction
* add comments
* minor refactoring
* make sure list up to limit
* update test
* update protolock file
* fix lint
* change per PR
We want to use those fields in the bucket-level Pointer objects as
bucket defaults, but we need to be able to get at them first.
I don't see any strong reason not to make these available, except
that it was kind of a pain.
