title: numpy.savetxt without hash mark at beginning of header line
body: <p>When I try to save a matrix with header, a hash mark and a space (# ) appear on the first line:</p>
  
  <p>input:</p>
  
  <pre><code>np.savetxt(filename,data, fmt='%i %i %i %i %s',delimiter='\t',header="a\tb\tc\td\te")
  </code></pre>
  
  <p>output:</p>
  
  <pre><code># a b   c   d   e
  0   0   0   0   bla
  0   0   0   0   bla
  1   1   1   1   bla
  1   1   1   1   bla
  </code></pre>
  
  <p>Any hint why? How could I remove it?</p>