Incompatible changes:

Incompatible changes:
* RRs with mailboxes never rejected due to strange chars if _raw.
* Lack of a mailbox produces `.' not `<>'.

Bugfixes and portability improvements:
* Mailboxes containing spaces in their names are quoted.
* adns_rr_hostaddr naddrs is -1 on temporary failure (as documented).
* Reject TXT RRs with no strings.