title: Disable html escaping inside backticks in python-markdown
body: <p>I observed, that python-markdown always escapes HTML entities inside backticks, even with safe=False:</p>
  
  <pre><code>In [1]: import markdown
  
  In [2]: markdown.markdown("&amp;amp;")
  Out[2]: u'&lt;p&gt;&amp;amp;&lt;/p&gt;'
  
  In [3]: markdown.markdown("*&amp;amp;*")
  Out[3]: u'&lt;p&gt;&lt;em&gt;&amp;amp;&lt;/em&gt;&lt;/p&gt;'
  
  In [4]: markdown.markdown("`&amp;amp;`")
  Out[4]: u'&lt;p&gt;&lt;code&gt;&amp;amp;amp;&lt;/code&gt;&lt;/p&gt;'
  </code></pre>
  
  <p>Is it a bug or a feature; is there a way to keep HTML entities unchanged?</p>