add merge_params.py

tools/merge_params.py

+import paddle.fluid as fluid
+import sys
+
+model_dir = sys.argv[1]
+new_model_dir = sys.argv[2]
+exe = fluid.Executor(fluid.CPUPlace())
+[inference_program, feed_target_names,
+ fetch_targets] = fluid.io.load_inference_model(dirname=model_dir, executor=exe)
+
+print(feed_target_names)
+fluid.io.save_inference_model(dirname=new_model_dir,
+                              feeded_var_names=feed_target_names,
+                              target_vars=fetch_targets,
+                              executor=exe,
+                              main_program=inference_program,
+                              params_filename="__params__")