title: p:dataTable never refreshes after a delete, update or insert
body: <p>Well, I have a p:dialog that inserts a new Entity, but after this entity is saved into database the p:dataTable remains the same, the new row doesn't appear. </p>
  
  <p>Look at my p:dialog:</p>
  
  <pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
  &lt;html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:ui="http://java.sun.com/jsf/facelets"
      xmlns:p="http://primefaces.org/ui"&gt;
  
  &lt;h:head&gt;
  
  &lt;/h:head&gt;
  &lt;h:body&gt;
      &lt;ui:composition&gt;
          &lt;h:form id="formCadastrar"&gt;
  
              &lt;p:dialog width="900px" height="500px" header="Cadastrar Dentista"
                  widgetVar="dialogCadastrar" modal="true"&gt;
  
                  &lt;p:panelGrid columns="2" styleClass="semBorda"&gt;
  
                      &lt;p:commandButton icon="ui-icon-disk" value="Salvar"
                          actionListener="#{dentistaMB.salvar}"
                          update=":formDentistas:dataTableDentistas" /&gt;
  
                      &lt;p:commandButton value="Cancelar" icon="ui-icon-close"
                          onclick="confirmCancelar.show()" type="button" /&gt;
  
                  &lt;/p:panelGrid&gt;
  
  
                  &lt;p:panelGrid id="panelGridCadastar" styleClass="semBorda"
                      columns="2"&gt;
                      &lt;h:outputText value="Nome: *" /&gt;
                      &lt;p:inputText id="nome"
                          value="#{dentistaMB.dentista.pessoaFisica.nome}" size="40"
                          required="true" requiredMessage="O Nome do Dentista é obrigatório"&gt;
                      &lt;/p:inputText&gt;
  
                      &lt;h:outputText value="CRO *" /&gt;
                      &lt;p:inputText id="cro" value="#{dentistaMB.dentista.cro}" size="10"
                          required="true" requiredMessage="O Número do CRO é obrigatório" /&gt;
                  &lt;/p:panelGrid&gt;
  
                  &lt;p:panelGrid columns="2" styleClass="semBorda"&gt;
                      &lt;p:commandButton icon="ui-icon-disk" value="Salvar"
                          actionListener="#{dentistaMB.salvar}"
                          update=":formDentistas:dataTableDentistas" /&gt;
  
                      &lt;p:commandButton value="Cancelar" icon="ui-icon-close"
                          onclick="confirmCancelar.show()" /&gt;
                  &lt;/p:panelGrid&gt;
  
                  &lt;p:confirmDialog id="confirmCancelar" message="Deseja cancelar ?"
                      showEffect="fade" hideEffect="fade" header="Cancelar"
                      severity="alert" widgetVar="confirmCancelar" appendToBody="true"&gt;
                      &lt;p:commandButton value="Sim" oncomplete="confirmCancelar.hide()"
                          actionListener="#{dentistaMB.cancelar}" /&gt;
                      &lt;p:commandButton value="Não" onclick="confirmCancelar.hide()"
                          type="button" /&gt;
                  &lt;/p:confirmDialog&gt;
  
              &lt;/p:dialog&gt;
  
          &lt;/h:form&gt;
      &lt;/ui:composition&gt;
  
  
  &lt;/h:body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>And look at my p:dataTable</p>
  
  <pre><code>&lt;h:form id="formDentistas"&gt;
  
                  &lt;p:growl autoUpdate="true" id="growlmessages" /&gt;
  
                  &lt;p:dataTable rowKey="#{dentista.id}" var="dentista" value="#{dentistaMB.dentistas}"
                      paginator="true" emptyMessage="Não foi encontrado nenhum registro"
                      rows="10" id="dataTableDentistas"
                      selection="#{dentistaMB.selectedDentista}" selectionMode="single"&gt;
  
                      &lt;f:facet name="header"&gt;Lista de Dentistas&lt;/f:facet&gt;
                      &lt;p:column headerText="Nome" sortBy="nome" filterBy="nome" id="nome"
                          width="200px"&gt;
                      #{dentista.pessoaFisica.nome}
                  &lt;/p:column&gt;
  
                      &lt;p:column headerText="Data Nascimento" sortBy="dataNascimento"
                          filterBy="dataNascimento" id="dataNascimento" width="60px"&gt;
                      #{dentista.pessoaFisica.dataNascimento}
                  &lt;/p:column&gt;
  
                      &lt;p:column headerText="CRO" sortBy="cro" filterBy="cro" id="cro"
                          width="60px"&gt;
                      #{dentista.cro}
                  &lt;/p:column&gt;
  
  
                      &lt;f:facet name="footer"&gt;
                          &lt;div class="align_text_left"&gt;
                          &lt;p:commandButton icon="ui-icon-plus" value="Novo" id="cadastrar"
                              oncomplete="dialogCadastrar.show()" /&gt;
  
                          &lt;p:column headerText="Ações" style="width:50px;"&gt;
                              &lt;p:commandButton value="Alterar" icon="ui-icon-pencil" /&gt;
  
                              &lt;p:commandButton value="Remover" icon="ui-icon-trash"
                                  action="#{dentistaMB.deletar}"
                                  update=":formDentistas:dataTableDentistas" /&gt;
                          &lt;/p:column&gt;
                          &lt;/div&gt;
                      &lt;/f:facet&gt;
  
                  &lt;/p:dataTable&gt;
              &lt;/h:form&gt;
  </code></pre>
  
  <p>So, what's the correct form to update the p:dataTable after a change in an entity? This example above is about an <em>insert</em>, but <em>remove</em> doesn't work either. I used the following code:</p>
  
  <pre><code>&lt;p:commandButton value="Remover" icon="ui-icon-trash"
                                  action="#{dentistaMB.deletar}"
                                  update=":formDentistas:dataTableDentistas" /&gt;
  </code></pre>