- 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.
