Fix: Added support to admin/ interface to list <role>s

This adds support to list global and per mount roles on stats.xsl.
This isn't nicest formated but works.
This also adds <source>-like <authentication> with <role>s to
root node.
Closes: #2133
Feature: Nicer display of <metadata>

This adds a little bit nicer display of <metadata> to the stats.xsl
page and avoids broken display of <metadata> and <authentication>.