[DAV] Add more metadata to DAVResources
Currently, AlekSIS does not answer to at least the following props:
(xmlns:d="DAV:" xmlns:ns2="LCGDM:")
<d:getlastmodified />
<d:creationdate />
<d:quota-used-bytes />
<d:collection />
<ns2:mode />
<d:owner />
<d:group />