*/*: add new port NGINX JavaScript (njs) command line utility

NGINX JavaScript, also knows as njs, is a subset of the JavaScript
language that allows extending nginx functionality.  njs is created
in compliance with ECMAScript 5.1 (strict mode) with some ECMAScript 6
and later extensions.  It's easy to use njs command line utility to
develop and debug additional functionality.  Also, it's light-weight
and very useful as a shebang in some cases as the nodejs substitutor.

Remove build of njs command-line utlity from the www/nginx-devel (*)
process.

Bump PORTREVISION. (*)