Captcha via altcha
I've implemented the captcha functionality, by adding a very simple widget provided by ALTCHA.
Therefore I also rebuilt the mailing functionality to a Flask based API which is now running on the support-apps VM and is handling the captcha-challenge and also the mail-send (incl. captcha-validity-check)
There is one issue related to this merge commit: #155 When you're fine with my changes and it also runs in your setup, than please give me a go for the merge or merge it directly ;)