Option to disable global average pooling?

[riaqn]

First of all, thank you for the efforts to improve and maintain the project even after the paper is published.

In my application I would like to do a more sophisticated pooling of the features. Currently I simply modify the call() method in Head class, and remove the line

      outputs = self._avg_pooling(outputs)

which I believe is enough. It would be useful as an options, I think; As the final global pooling is not a "critical" part of the CNN, and we should leave it to the user to decide what pooling they want.