Unbreak Let's Encrypt support

Update all dependencies and fix handling of TLS ALPN.
This makes certification requests to Let's Encrypt work again.

Use acme v02 by default

Update config example and default URLs to use v02 of the acme API.
V01 is long gone and no longer supported by Let's Encrypt.

Only allow TLS >= TLS 1.2

v0.4.1

Only allow >= TLS 1.2

Apple mobileconfig support and easier debugging

Koni now supports generation of mobileconfig.xml files for iPads and iPhones:

https://koni.example.com/mobileconfig.xml?emailaddress=me@example.com

Ro enable complete request/response logging, set the following in koni.conf:

debug = yes

First version that seems to work OK

v0.3.0

Various fixes