This commit makes NM code to report HTTP as a stream protocol. This
makes it possible to handle large responses properly. Like:
dig +https @127.0.0.1 A cmts1-dhcp.longlines.com
- rename dot to doth, as it now covers both dot and doh.
- merge xot into doth as it's closely related.
- added long-lived key and cert files (expiring 2121).
- add tests with https-get, https-post, http-plain, alternate
endpoints, and both static and ephemeral TLS configuration.
- incidentally fixed a memory leak in dig that occurred if +https
was specified more than once.