title: Seaborn FacetGrid col_wrap (wide to long) plotting issue
body: <p>I am trying to plot each row(in wide table) using Seaborn's FacetGrid and <code>col_wrap</code>.</p>
  
  <p>First I convert wide to long:<br>
  -- <code>stack()</code> the wide data to a series, <code>s</code>.<br>
  -- use <code>get_level_values</code><br>
  -- append the series to the dataframe  </p>
  
  <p>FacetGrid only plots the first plot though ? </p>
  
  <pre><code>dt1 = pd.DataFrame({'s1':[0,1,2,3,4], 's2':[4,2,3,6,7], 's3':[6,7,3,4,7] })
  def fct(data):
      #toy model dataframe
      #dt1.index.names = ['ind']
      dt = data.stack()
      dt.index.names = ['i','s']
      ind = pd.Series( dt.index.get_level_values(0).values )
      sub = pd.Series( dt.index.get_level_values(1).values )
      dtt = pd.DataFrame( ind , columns=['ind'])
      dtt['sub'] = sub
      dtt['ind'] = ind
      dtt['dt'] = dt.values
      #dt.reindex(columns='v')
      print ( 'dt ', dtt.describe)
      g = sns.FacetGrid( dtt, col='sub', col_wrap=1, size=2, ylim=(0, 10) )
      g.map( sns.pointplot, 'ind', 'dt', color=".3", ci=None );
  </code></pre>
  
  <p>`</p>
  
  <p><img src="https://i.stack.imgur.com/yJaEB.png" alt="enter image description here"></p>