lynx-dev release page fixes

[Vlad Harchev]

 Here are my corrections for http://lynx.isc.org/release/features.html

>     * add  colored  source  view for curses, command line option --pret-
>       tysrc.

   prettysrc is available for slang too, so this text could be misleading.

>     + since  DIV is a block element, make sure its contents don not
                                                                ^^^

 Best regards,
  -Vlad