compile behaviour first

Author: kuenishi

rebar.config

@@ -5,6 +5,11 @@
 {edoc_opts, [{dialyzer_specs, all}]}.
 {validate_app_modules, true}.
 
+{erl_first_files, [
+                   "src/msgpack_ext.erl"
+                  ]}.
+
+
 %% {port_sources, ["c_src/*.c"]}.
 %% {port_env, [
 %% 	     %% Make sure to set -fPIC when compiling leveldb