Previously, onionAddresses definitions in onionServices were of the form
onionAddresses.access.<service> = [<service>];
This caused failures for configurations where a service user name was
overridden or for bitcoind whose default user is 'bitcoin' instead of 'bitcoind'.
Now set the equivalent of:
onionAddresses.access.<actualServiceUser> = [<service>];
Implement this via a new option `onionAddresses.services` to make things more
readable and to work around an infinite recursion error in onionServices.
- use -e to check for existence of /var/lib/tor/state, use shorter
polling interval
- clear existing dataDir contents to avoid accumulating obsolete data
- use concatMapStrings instead of foldl'
