title: Hbase Scan Filter for Records that are Missing Column or the Column Value is null
body: <p>I have 3 cols {col1, col2, col3} in a col family (CF).  I'd like to write a scan such that I select all rows that have <code>col1='val1' and col2='val2' and (col3 is missing or col3 is null)</code>.</p>
  
  <p>Doing this in Java - sorry I'm totally new to hbase ;-)</p>