Remove coupling from sitetree.
Remove coupling from sitetree.

nyeholt/silverstripe-solr,stephenmcm/silverstripe-solr,stephenmcm/silverstripe-solr,nyeholt/silverstripe-solr,stephenmcm/silverstripe-solr,stephenmcm/silverstripe-solr,nyeholt/silverstripe-solr,nyeholt/silverstripe-solr