Allow * wildcard in trusted_domains to support unstable DNS names and unstable IP addresses

I'm not quite understanding how ownCloud releases are produced from git, nor how to run the tests, and so I don't quite know how to test this. I'm hoping that a friendly soul will advise and/or merge. Thanks.
Corresponding pull requests to docs coming.
Also here: No spaces please. - Also we might want to simplify this. But first let me help you to get PHPUnit running :-)