Merge pull request #395 from arokem/master

Typo fixed.
Merge pull request #397 from PierreR/master

Update to 0MQ4 + cleanup
Python 3 compatibility for Chapter 1
Python 3 compat for Chapter 2
Python 3 compatibility for Chapter 3
Merge pull request #398 from minrk/py3

Python 3 compatibility for Chapters 1-3
Updated text
Rebuilt Guide
Correct README