Display message on HTTP 400

This patch parses the faultstring given by the server on 400 errors if
available.

Change-Id: Ieae2f0b39fed2c45f276d6c931bebfebab9f696e
Closes-Bug: bug #1260394
Merge "Display message on HTTP 400"
Python 3: use six.moves.zip() rather than itertools.izip()

This ensures compatibility with both Python 2 and Python 3.

Change-Id: Id9838b7517f939e5ee3e3a8c37ae5ec2e9b1d18b