config.ta_update test doesn't play along with others and wants all of
the runner's attention to itself, otherwise it throws a tantrum.

Using 443 as the default port presents too many packaging challenges.
DoH requires configuration to be useful anyway, so users are free to
override this value as they see fit.

Older cqueues may cause some issues with lua-http

modules/http: fix too early renewal of ephemeral certificates

See merge request knot/knot-resolver!808

http.config() fixes

See merge request knot/knot-resolver!807

Formerly http.config({tls=false}, 'doh') also removed all endpoints for
'doh', which was unexpected.

With this change configurations are merged as expected and user does not
have to repeat endpoints and other options from builtin template.

http sockets

Closes #85

See merge request knot/knot-resolver!803

Output buffering in tests made debugging much harder because crash in
middle of operation discarded while buffer and left us without a trace
what was going on.

We still need to somehow solve socket closure etc.

Add interface for providing different named configuration sets.
This will be handy once we start getting named sockets from systemd.

Now we hopefully won't need to touch it for a long time.

- allow omitting port number
- sync docs
- fix memory leak
- fix with kind != NULL