Log Message:
www/nginx-devel: decouple from www/nginx

It's not a typical practice in pkgsrc to share options.mk.  Also, it's
not easy to build both www/nginx and www/nginx-devel with a different
set of options.  So, let's decouple www/nginx-devel from www/nginx.

From now the following option needs to be specified to build
www/nginx-devel with a specific options: PKG_OPTIONS.nginx-devel.

While I'm here add support to build package with devel/pcre2. Please
note: some third-party modules, such as naxsi and luajit, are not
compatible yet with devel/pcre2, so let's keep pcre option as a
suggested one.

Bump PKGREVISION.