* For now, import pythontools only give access to core features. This will change in the future.

Do not loop access on tango devices, use group access.

* Add a little more debug messages.
* If attribute is numpy array, convert to python list.
  We have to do so to serialize with json.
* Catch exception when trying to access attribute.
  We signal a warning. The defualt case is with an attribute that has
  no name...

And not an array anymore.

* Peut scanner un ou plusieurs devices
* Scanne les attributs writtable
* Scanne les properties
* Exporte au format JSON, eventuellement dans un fichier