Modernization of Erlang ports:
- Convert all ports to options helpers
- Add MANPAGES option to lang/erlang
- Remove HTML and PDF documentation from lang/erlang (went into erlang-doc)
- Remove APP_UPGRADE code because of the doc split
- Reduce diffs between all Makefiles
- Enable dirty schedulers by default on version 20
- Non-SMP beam is deprecated on version 20, so enable SMP unconditionally