Add simple escript to modify advanced.config.

In the future we should fix the tests to actually use a non-test
backend configuration properly, but for now we can apply our
customization directly to the advanced.config file, even against
riak_ee which will ship with settings already in advanced.config.

buildbot/Makefile

@@ -7,7 +7,7 @@ RIAK_ADMIN = ${RIAK_DIR}/bin/riak-admin
 preconfigure:
 	echo "storage_backend = memory" >> ${RIAK_CONF}
 	echo "anti_entropy = passive" >> ${RIAK_CONF}
-	echo "[{riak_kv,[{test,true}]}]." > ${ADVANCED_CONF}
+	./add_to_advanced_config ${ADVANCED_CONF} '{riak_kv,[{test,true}]}.'
 	echo "search = on" >> ${RIAK_CONF}
 	echo "listener.protobuf.internal = 127.0.0.1:8087" >> ${RIAK_CONF}
 	echo "distributed_cookie = riak" >> ${RIAK_CONF}

buildbot/add_to_advanced_config

@@ -0,0 +1,11 @@
+#!/usr/bin/env escript
+%% -*- erlang -*-
+main([File|Additions]) ->
+    {ok, Settings} = file:consult(File),
+    Terms = [ begin
+                  {ok, Tokens, _} = erl_scan:string(String),
+                  {ok, Term} = erl_parse:parse_term(Tokens),
+                  Term
+              end || String <- Additions ],
+    Merged = lists:flatten(Terms++Settings),
+    file:write_file(File, io_lib:format("~p.",[Merged])).