New structure -- review requested about greg

[FilipBB]

Looks good to me, maybe pretty_print() should be moved to auxiliary functions? Or merge it into the "info" command? It doesn't seem to be used anywhere else, and that would keep commands.py to strictly the commands greg implements on the command line.

[Narrat]

Looking good to me, too.
What could also be done is to rename the two functions in aux which doesn't follow the general naming convention? (htmltotext --> html_to_text; FeedburnerDateHandler --> feedburner_date_handler)

[manolomartinez]

Thanks, this is now in master, with both your suggestions accepted.