title: how to query from customer RevisionEntity in Hibernate Envers?
body: <p>i'm using  Hibernate Envers,my customer RevisionEntity is:</p>
  
  <pre><code>@Entity
  @RevisionEntity(SimpleListener.class)
  @Table(name = "data_rev_info")
  public class SimpleRevisionEntity {
      @Id
      @GeneratedValue
      @RevisionNumber
      @Column(name = "revision_id")
      private long id;
  
      @RevisionTimestamp
      @Column(name = "revision_timestamp")
      private Date timestamp;
      /**
       * @return the id
       */
      public long getId() {
          return id;
      }
      /**
       * @param id the id to set
       */
      public void setId(long id) {
          this.id = id;
      }
      /**
       * @return the timestamp
       */
      public Date getTimestamp() {
          return timestamp;
      }
      /**
       * @param timestamp the timestamp to set
       */
      public void setTimestamp(Date timestamp) {
          this.timestamp = timestamp;
      }
  }
  </code></pre>
  
  <p>i can use auditReader to get audit time of a specific revision id</p>
  
  <pre><code>AuditReader auditReader = AuditReaderFactory.get(em);
  Date date = auditReader.getRevisionDate(n);
  </code></pre>
  
  <p>if i add a additonal field in SimpleRevisionEntity, named actor(type is String),how to get this addtional field by using AuditReader? 
  Also if i want to query audit logs generated in the last five minites,how to?</p>