title: Get all families in hbase
body: <p>I have a hbase table with </p>
  
  <blockquote>
    <p>Rows: word, Families: date</p>
  </blockquote>
  
  <p>I want to get a scanner for all the words at the date 'd', how I can do this? So I don't want to specify the row value.</p>