Hosting multiple domains

Hello all,

let me introduce myself first: My name is Timotheus Pokorra, and I now
work for TBits in the south of Germany.
I have had contact with the Kolab project already 10 years ago, I have
written my diploma thesis about Exchange alternatives
(http://www.pokorra.de/groupware/howto/kolab_toltec.html)
I am glad that Kolab has developed and improved steadily over the
years, and I am already enjoying to work with TBits who are hosting
Kolab for many customers.

As the task of migrating from Kolab2 is now on me, I have written this
blog post about support for multiple domains in Kolab3:
http://www.tbits.net/tbits-opensource/kolab3multipledomains.html
It is based on the Administrators Guide and various blog posts and
mailing list posts. Thanks for that!
I have tried to put the instructions into scripts that can be executed
easily from the command line.

You find the code linked to my solution in this gist:
https://gist.github.com/tpokorra/5244642

I am looking for feedback and suggestions to improve this.

Especially the patch to Roundcube, for support of multiple domains
without changing the config files or requiring several hosts. I have
not fully tested it, and I don't know the rules and conventions of the
Roundcube project (yet).

All the best,
  Timotheus