Removes all of the from __future__ imports that open and close the
brackets on the same line. This is most of them.

Also updated class_maker.py

This allows axes autoscaling to take place after plotting if the
limits have not been changed

Make sure __future__ imports are in every file
Use existing context manager to block QSignals
Rename artist_has_errorbars -> artists_workspace_has_errors

Sort tests in CMakeLists