Also fixes non-recursive resolve erring instead showing one step.

 The patch of core/commands/resolve.go could be done better but I don't
 know how to get access to ErrResolveRecursion.

 It allows for dnslinks into sub-segments. So for example hosting
 multiple blogs
 on just domains from one pubkey.

 Fixes #2059

 Add tests and fix case when dnslinks references dnslink

License: MIT
Signed-off-by: Jakub (Kubuxu) Sztandera <kubuxu@gmail.com>