- Fix bucket delete
- fix merge of bucket creation date
- Replace deletable with option in aliases
Rationale: if two aliases point to conflicting bucket, resolving
by making an arbitrary choice risks making data accessible when it
shouldn't be. We'd rather resolve to deleting the alias until
someone puts it back.
- ensure bucket names are correct aws s3 names
- when making aliases, ensure timestamps of links in both ways are the
same
- fix small remarks by trinity
- don't have a separate website_access field
