PHPCR Fixes to make it work

Changes are basically correcting PHPCR mapping files, commenting method in BaseGallery which was causing troubles (we need to take a look to it) and correct wrong class names in repositories.
@dbu I've tried a new project with this PR and seems that skipping this PR (so, method is uncommented and executed) is working perfectly on Production. I can't test in DEV because IDK why I'm getting `An exception has been thrown during the rendering of a template ("Parameter "id" for route "admin_sonata_media_media_edit" must match ".+" ("" given) to generate a corresponding URL.") in SonataMediaBundle:MediaAdmin:inner_row_media.html.twig at line 19.
` which is weird as fuck because everything is configured like before...