When having multipe hosts on one line the virtualhost configuration, make sure they are merged correctly

Normally, when you would like to configure a host for preview.onehippo.org and www.onehippo.org, you would configure:

org
` onehippo

now, also allowed is:

www.onehippo.com
preview.onehippo.com

Only, this second version, is still being translated into an in memory tree model, only, 'org' is in this time represented twice.

We have to make sure, that preview.onehippo.com does not override www.onehippo.com. but that it gets merged.