title: gnuplot: line break following a comment line
body: <p>Why this code doesn't work?</p>
  
  <pre><code>plot \
  #sin(x),\
  cos(x)
  </code></pre>
  
  <p>the error info is</p>
  
  <pre><code>plot 
       ^
  "a.plt", line 3: function to plot expected
  </code></pre>
  
  <p>gnuplot --version</p>
  
  <pre><code>gnuplot 5.0 patchlevel 0
  </code></pre>