* Objectives:
- make easier to read and maintain
- 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
CHANGES 20180313
* Separate bundled and 3rd party modules
* Order options alphabetically
* Pass openssl dir to configure
* Separate external modules in separate makefile
TODO
* DSO_EXTMODS doesn't work
* Check WWWDATA PLIST_SUB duplicates