Increase revocation message/blob maximum size
FetchResult's ClientMetadata should not be null.
Revocation fetch failed from blob file message: Reduce duplication, identify when they've changed the key.
No redirects, no archives, no splitfiles, etc. Revocation must fit in a single SSK block.
More thorough explanations when there is a problem with auto-update blow.
Localise the two revocation-fetch-fatally-failed panic messages.
Make the revocation message a bit more human-readable.
Make it a little more readable (paragraphs), and more work on the l10n.