we decided we want to follow jcr in this case, so we really should i think: http://www.day.com/maven/javax.jcr/javadocs/jcr-2.0/javax/jcr/query/qom/QueryObjectModelFactory.html#selector%28java.lang.String,%20java.lang.String%29

if we don't we can undo most of this PR i did, but i would be rather unhappy, as we said in https://github.com/phpcr/phpcr/issues/34 and on irc, we want to follow jcr. it would have been quite a waste of time if we now change our mind again.