Configuration test xml

follow-up for #103 - there are some issues with xml that i hope somebody can help me with.

until #103 is merged, this will also show all changes of #103
btw, the usage as ``cache-control`` as the singular name for the prototyped array-node tag while it matches the name of the array node will not work properly for XML files (try defining a file with several directives).

I suggest using ``<cache-control-directive name="public">true</cache-control-directive>`` instead (as each tag represent a single directive) and using ``->fixXmlConfig('cache-control-directive', 'cache-control')``