sthen@ found that the mailcap mechanism can spawn a viewer. Rename
the hardcoded /etc/mailcap and ~/.mailcap files to /dev/null and
disable the ability to undo that via a config file. lynx copes by
offering to download files with MIME types it can't handle itself.
fcambus found that "lynx index.html" + typing e spawns an editor.
Hardcode "no_editor = TRUE" before pledge() and tweak manpage.
Most of this is by fcambus (MAINTAINER).
/dev/null bit from me, based on a hint from sthen@.
ok sthen@ on previous version
a4e7464812