Registrar un usuario en drupal usando jQuery y REST, cortesía de @jmruvalcabav

drupal-user-register-rest.js

var user = {
_links: {
  type: {
    href: 'http://192.168.100.106:81/rest/type/user/user'
  }
},

name:[{'value':'user'}],
pass:[{'value':'pass'}],
status:[{'value':true}],
mail:[{'value':'example@example.com'}],
langcode:[{'value':'en'}],
roles:[{'target_id':'editor','target_type':'user_role'}],
field_publication:[{"target_id":"1","target_type":"taxonomy_term","url":"http://192.168.100.106:81/taxonomy/term/1"}]
//field_prueba:[{"value":"prueba"}]
//user_picture:[{ "target_id":"2354"}]
};

jQuery.ajax({
  url: 'http://192.168.100.106:81/entity/user',
  method: 'POST',
  headers: {
    authorization: 'Basic YWRtaW46YWRtaW4x', // user:pass base64
    'Content-Type': 'application/hal+json'    },
  'data': JSON.stringify(user)
  ,
  success: function (response) {
    //Response
    console.log("Response:");
    console.log(response);
  },
  error: function (error){
    //Error
    console.log("Error:");
    console.log(error);
  }
});