New CSV Logger (#4148)

* New CSV Logger

* cleanup

* move batch plots into Logger

* rename comment

* Remove total loss from progress bar

* mloss :-1 bug fix

* Update plot_results()

* Update plot_results()

* plot_results bug fix

val.py

@@ -171,7 +171,7 @@ def run(data,
 
         # Compute loss
         if compute_loss:
-            loss += compute_loss([x.float() for x in train_out], targets)[1][:3]  # box, obj, cls
+            loss += compute_loss([x.float() for x in train_out], targets)[1]  # box, obj, cls
 
         # Run NMS
         targets[:, 2:] *= torch.Tensor([width, height, width, height]).to(device)  # to pixels