title: Multiline latex header from src block
body: <p>I have several lines that should be added before <code>\begin{document}</code>. Usually, I do that with <code>#+LATEX_HEADER:</code>.  However, <code>#+LATEX_HEADER:</code> is not able to evaluate references (e.g., noweb) nor org macros. The only solution I can see is to add <code>#+LATEX_HEADER:</code> before each line. Is there a more elegant way to do that?</p>
  <p>My &quot;ideal&quot; org file (not working):</p>
  <pre><code>#+TITLE: Title
  #+AUTHOR: Someone
  
  #+LATEX_CLASS: article
  
  #+LATEX_HEADER: &lt;&lt;headerthings&gt;&gt;
  
  * First Section
  Lorem Ipsum is simply dummy text of the printing and typesetting
  industry. Lorem Ipsum has been the industry's standard dummy text ever
  since the 1500s, when an unknown printer took a galley of type and
  scrambled it to make a type specimen book. 
  
  * header things                                                    :noexport:
  #+name: headerthings
  #+begin_src latex
  \somemacro{
  Morbi rutrum eros 
  luctus. Maecenas n
  nunc nec vulputate
  diam in urna. Susp
  gravida nisl a lor
  ullamcorper sodalet
  per conubia nostra
  eros. In mollis el
  convallis laoreet.
  efficitur aliquet 
  }
  #+end_src
  </code></pre>
  <p>Non-elegant working solution:</p>
  <pre><code>#+TITLE: Title
  #+AUTHOR: Someone
  
  #+LATEX_CLASS: article
  
  #+LATEX_HEADER: &lt;&lt;headerthings&gt;&gt;
  
  * First Section
  Lorem Ipsum is simply dummy text of the printing and typesetting
  industry. Lorem Ipsum has been the industry's standard dummy text ever
  since the 1500s, when an unknown printer took a galley of type and
  scrambled it to make a type specimen book. 
  
  * header things                                                    :noexport:
  #+LATEX_HEADER: \somemacro{
  #+LATEX_HEADER: Morbi rutrum eros 
  #+LATEX_HEADER: luctus. Maecenas n
  #+LATEX_HEADER: nunc nec vulputate
  #+LATEX_HEADER: diam in urna. Susp
  #+LATEX_HEADER: gravida nisl a lor
  #+LATEX_HEADER: ullamcorper sodalet
  #+LATEX_HEADER: per conubia nostra
  #+LATEX_HEADER: eros. In mollis el
  #+LATEX_HEADER: convallis laoreet.
  #+LATEX_HEADER: efficitur aliquet 
  #+LATEX_HEADER: }
  </code></pre>