What does Eleanor Roosevelt mean when she says, “...giving our approval to the declaration today it is of primary importance that we keep clearly in mind the basic character of the document. It is not a treaty; it is not an international agreement. It is not and does not purport to be a statement of basic principles of law or legal obligation. It is a declaration of basic principles of human rights and freedoms, to be stamped with the approval of the General Assembly by formal vote of its members, and to serve as a common standard of achievement for all peoples of all nations”?