title: How to specify docstring for __init__ in Python C extension
body: <p>Perhaps a stupid question:
  how can one specify docstring for special functions like <code>__init__</code> when writing a C extension?
  For ordinary methods, method table has provision for docstrings. The following autogenerated documentation is displayed when I try help(myclass): </p>
  
  <pre><code>  __init__(...)
        x.__init__(...) initializes x; see help(type(x)) for signature
  </code></pre>
  
  <p>But this is what I want to override.</p>