erlang: add Makefile and rebar.config for building with rebar3

erlang/Makefile

@@ -0,0 +1,35 @@
+REBAR3=$(shell type -p rebar3 || echo ./rebar3)
+REBAR3_GIT=https://github.com/erlang/rebar3.git
+REBAR3_VSN=3.7.5
+
+PROGRAMS=8to9
+
+default: compile link
+
+compile:	$(REBAR3)
+	$(REBAR3) compile
+
+link:	$(REBAR3)
+	for PROG in $(PROGRAMS); do \
+		rm -f _build/$$PROG; \
+		ln -s default _build/$$PROG; \
+		$(REBAR3) as $$PROG escriptize; \
+	done
+
+distclean realclean:	clean
+	rm -f ./rebar3
+
+clean:	$(REBAR3)
+	$(REBAR3) clean
+	rm -rf _build
+
+./rebar3:
+	mkdir -p _build; \
+	cd _build; \
+	git clone --quiet $(REBAR3_GIT); \
+	cd rebar3; \
+	git checkout --quiet $(REBAR3_VSN); \
+	./bootstrap; \
+	mv rebar3 ../../; \
+	cd ../..; \
+	rm -rf _build/rebar3

erlang/rebar.config

@@ -0,0 +1,19 @@
+%% -*- erlang -*-
+{eunit_opts, [verbose, {report, {eunit_surefire, [{dir, "."}]}}]}.
+
+{erl_opts, [ debug_info
+           , warn_unused_vars
+           , warn_shadow_vars
+           , warn_unused_import
+           , warn_obsolete_guard
+           , warnings_as_errors
+           ]}.
+
+{deps, []}.
+
+{escript_emu_args, "%%! +sbtu +A1 +Bd -noshell -smp auto\n"}.
+
+{profiles,
+  [
+      {'8to9', [{escript_main_app, '8to9'}]}
+  ]}.