code: def xmlFile(path, mode='r'):
      
      fh = file(path, mode)
      while fh.read(1) != '<': # Ignoring everything before '<?xml...'
          pass
      fh.seek(-1, 1)
      return fh
docs: lxml cannot parse XML files starting with a BOM
      (see http://www.w3.org/TR/2000/REC-xml-20001006 in F.1.)
      In case such XML file is used, we must skip these characters
      So we open all XML files for read with 'xmlFile'.
      TODO: File this issue to lxml ML or tracker (feature or bug ?)
  
      :param path: The path to the file
      :param mode: Mode for opéning the file