* disable endless retry logic
- we should do the retry logic at application cmd/ro, cmd/ro will need to
deal with keyboard interrupts as well
* update test self-signed certificate with a expiry of 100 years
* ro tool supports retries after getting delegation errors
This change addresses several points:
1. The integration tests didn't verify that delegations could be used
for decryption following a restore. The integration tests now
verify this.
2. There was no functionality for clearing persisted delegations if
needed. The vault admin can now do this via the command line tool.
3. Restoring active delegations wasn't storing the key with the
delegation. Keys are now serialised properly.
4. [Minor] The MSP package now reports the name of the offending user
when it can't find a user name in the database.
+ persistLabels moved from cryptor to persist package global.
+ Restore now explicitly checks for the case where there aren't enough
shares to return `ErrRestoreDelegations`.
+ The users responsible for restoring the cache are now logged.
