Modernize Python 2 code to get ready for Python 3

[cclauss]

Make the minimal, safe changes required to convert the repo's code to be syntax compatible with both Python 2 and Python 3. More work will be required to complete a port to Python 3 but this is a minimal, safe first step.

• futurize stage 1
• print() function
• from future import absolute_import
• octal numbers (0077 --> 0o077)
• new style exceptions

Signed-off-by: cclauss cclauss@bluewin.ch