Draft: Update Kmails auto encrypt feature
Actually it is a lot changes in this branch:
- auto-encryption code in KMail's composer to use the Trust Levels (from Kleo::trustLevel()) and adjusts the description strings accordingly. ( https://phabricator.kde.org/D4460)
- Use KeyResolverCore to determine best keys.
- Show directly in Compose if keys are near to expire not only after you want to send the mail.
- Make it possible to solve the key selection before hitting send.