* Check if dateutil is indeed  (>= 1.5) -- absent on Ubuntus
* IPython 0.11 seems to be required to build docs
  - there was a bug report requesting -doc iirc
* adjust copyright to mention code in setup.py borrowed from pyzmq
* gather more of copyright/license added in 0.8.
* Pytest's xdist plugin boosts the unittest speed significantly.
  (python3-pytest-xdist)
