title: mechanize: first form works, then "unknown GET form encoding type 'utf-8'"
body: <p>I am trying to fill out 2 forms from the EUR-Lex website in order to record some data from the generated webpage.
  I am stuck at form #2. I get the feeling this should be easy and I've researched a bit, but no luck.</p>
  
  <pre><code>import mechanize
  
  froot = '...'
  f = open(froot + 'text.html', 'w')
  
  br = mechanize.Browser()
  br.open('http://eur-lex.europa.eu/RECH_legislation.do')
  br.select_form(name='form2')
  br['T1'] = ['V112']
  br['T3'] = ['V2']
  br['T2'] = ['V1']
  
  first_page = br.submit()
  f.write(first_page.get_data())
  </code></pre>
  
  <p>up until here everything seems to work, because I get the source of the correct page saved to the file. But then...</p>
  
  <pre><code>br.select_form(name='form2')
  br['typedate'] = ['PD']
  
  br['startaaaa'] = '1960'
  br['startmm'] = '01'
  br['startjj'] = '01'
  br['endaaaa'] = '1960'
  br['endmm'] = '12'
  br['startjj'] = '31'
  
  next = br.submit()
  </code></pre>
  
  <p>here everything stops: </p>
  
  <pre><code>ValueError: unknown GET form encoding type 'utf-8'
  </code></pre>
  
  <p>I checked <code>br.enctype</code> before selecting the first and second forms. What I get is:</p>
  
  <ul>
  <li>after the first form: <code>application/x-www-form-urlencoded</code></li>
  <li>after the second form: <code>utf-8</code></li>
  </ul>
  
  <p>I don't know what is going on here.</p>