attach_name()
  Attachment name scanner.
  
  This scanner checks defined name of file in mime attachments.
  By default known executable extensions will be blocked.
  This scanner can be used only if it's parent is parsemail().
  
  Usage: attach_name({b'VirName': b'regexp_pattern', ..}, flags=re.I)
  
  Where: 'VirName' is a string, which defines virus name
         'regexp_pattern' is an regular expression. If this expression
           is found in attachment's name, VirName is returned
           as virus name.
         flags is a number, which defines regular expression flags.
           By default IGNORECASE is used.
  
  Example: attach_name({
             'Executable': '\.(exe|com|vxd|dll|cpl|scr|pif|lnk|bat|vbs|js)$'
           })