Sorting out some Erlang stuff:
- Rename a few Erlang-related ports using the erlang- prefix; it will avoid confusion with elixir- ports. - Remove DOCS and EXAMPLES where not actually useful. - Simplify RUN_DEPENDS where possible. - Move textproc/exmpp to devel/erlang-exmpp. - Add missing R18 compatibility fix for devel/erlang-oserl. - Upgrade erlang-cuttlefish to 2.0.3. The idea is that libraries ("deps") have the "erlang-" prefix, while larger projects (rabbitmq, yaws, couchdb, etc) keep their usual names.