www/nginx: make easier to read and maintain:
* Objectives:
- make easier to read and maintain
- Module config in a single section
- use OPTIONS framwework where possible
* Add options groups for mail and http
* Use options groups to set _IMPLIES instead of large .if HTTP and MAIL blocks
* Rename all _VERSION vars to align with the OPTION name
* Add DEVEL_KIT option so we can automate
* Separate bundled and 3rd party modules
* Order options alphabetically
* Pass openssl dir to configure
* Separate external modules in separate makefile
www/nginx is buildable again with this:
* Fix sub-paths for DSO_EXTMODS introducing ${WRKSRC_mod}
* Be smarter about the if ${PORT_OPTIONS:MDSO}
* move post-install-OPT-on to where possible
* Add some OPT_NGINX_VER if used multiple times