Multiple improvements and bug fixes (#66)

* Multiple improvements and bug fixes:

    * Using lazy stacking to save on memory when using a replay buffer
    * Remove step counting for evaluation episodes
    * Reset game between heatup and training
    * Major bug fixes in NEC (is reproducing the paper results for pong now)
    * Image input rescaling to 0-1 is now optional
    * Change the terminal title to be the experiment name
    * Observation cropping for atari is now optional
    * Added random number of noop actions for gym to match the dqn paper
    * Fixed a bug where the evaluation episodes won't start with the max possible ale lives
    * Added a script for plotting the results of an experiment over all the atari games

coach.py

@@ -34,11 +34,6 @@ import sys
 import subprocess
 from threading import Thread
 
-try:
-    from Queue import Queue, Empty
-except ImportError:
-    from queue import Queue, Empty # for Python 3.x
-
 if len(set(failed_imports)) > 0:
     screen.warning("Warning: failed to import the following packages - {}".format(', '.join(set(failed_imports))))
 
@@ -258,7 +253,8 @@ if __name__ == "__main__":
     # dump documentation
     logger.set_dump_dir(run_dict['experiment_path'], add_timestamp=True)
     if not args.no_summary:
-        atexit.register(logger.print_summary)
+        atexit.register(logger.summarize_experiment)
+        screen.change_terminal_title(logger.experiment_name)
 
     # Single-threaded runs
     if run_dict['num_threads'] == 1:
@@ -300,7 +296,7 @@ if __name__ == "__main__":
            "--worker_hosts={}".format(worker_hosts),
            "--job_name=ps",
         ]
-        parameter_server = Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, bufsize=1)
+        parameter_server = Popen(cmd)
 
         screen.log_title("*** Distributed Training ***")
         time.sleep(1)
@@ -325,7 +321,7 @@ if __name__ == "__main__":
                             "--job_name=worker",
                             "--load_json={}".format(json_run_dict_path)]
 
-            p = Popen(workers_args, stdout=subprocess.PIPE, stderr=subprocess.PIPE, bufsize=1)
+            p = Popen(workers_args)
 
             if i != run_dict['num_threads']:
                 workers.append(p)