New "make relive" similar to "ejabberdctl live" without installing

Prepare with:
  ./autogen.sh && ./configure --with-rebar=./rebar3 && make
Or use this if you installed Elixir:
  ./autogen.sh && ./configure --with-rebar=mix && make
Start without installing (it recompiles when necessary):
  make relive
It stores config, database and logs in _build/relive/
There's available the well-known script:
  _build/relive/ejabberdctl

Please note this fails immediately:
  r3:do(compile).
This crashes a few seconds later:
  rebar3:run(["compile"]).
Workaround that works correctly:
  ejabberd_admin:update().

rel/relive.escript

@@ -0,0 +1,26 @@
+#!/usr/bin/env escript
+
+main(_) ->
+    Base = "_build/relive",
+    prepare(Base, "", none),
+    prepare(Base, "conf", {os, cmd, "rel/setup-relive.sh"}),
+    prepare(Base, "database", none),
+    prepare(Base, "logs", none),
+    c:erlangrc([os:cmd("echo -n $HOME")]),
+    ok.
+
+prepare(BaseDir, SuffixDir, MFA) ->
+    Dir = filename:join(BaseDir, SuffixDir),
+    case file:make_dir(Dir) of
+        ok ->
+            io:format("Preparing relive dir ~s...~n", [Dir]),
+            case MFA of
+                none -> ok;
+                {M, F, A} -> M:F(A)
+            end;
+        {error, eexist} ->
+            ok;
+        {error, LogsError} ->
+            io:format("Error creating dir ~s: ~p~n", [Dir, LogsError]),
+            halt(1)
+    end.