Bulk python3 print port

[github at samba.org]

New comment by frenzymadness on Samba Github repository

https://github.com/samba-team/samba/pull/146#issuecomment-375617200
Comment:
Hello.

I did a quick review and I have just two nitpicks:
* It would be nice to unify all empty prints to `print("")` but more preferably to  `print()`.
* It would be also nice to fix indentation in places where `file=sys.stderr` is moved at the end of lines. For example: https://github.com/samba-team/samba/pull/146/files#diff-c9a916b89694bec111daf93eb63b8b47R196

Consider my notes as just ideas becuae they have no impact to actual functionality.

Now it seems that CI is passing so we might be ready for a merge.

Thanks a lot!