I create a new page with my nginx config to cover all changes and mods which I've done on my Raspberry Pi.
The instructions are based on http://kolab.org/blog/grote/2013/07/08/using-kolab-3-nginx and https://docs.kolab.org/howtos/nginx-webserver.html.
So feel free to leave any comments and to get your Kolab running on your Pi with a bit more performance.
More tuning tips are welcome. :-)