[carla] In carla example, save all images and measurements to local disk (#1350)

* revamp saving

* smaller jpgs

* hide verbose

* Tue Dec 19 22:25:01 PST 2017

* make sure temp dirs sort lexiographically

* save total reward too

* zero pad i

* 160x160 dqn

* ever higher res dqn

examples/carla/train_ppo.py

@@ -9,6 +9,7 @@ from env import CarlaEnv, ENV_CONFIG
 env_name = "carla_env"
 env_config = ENV_CONFIG.copy()
 env_config.update({
+    "verbose": False,
     "x_res": 80,
     "y_res": 80,
     "use_depth_camera": True,