Training Set Release

Description

Edits to nearly every case in one way or another.

[x] Merged latest master
[x] Updated version number in README.md
[x] Added changes to changelog.md
[x] Updated version number in setup.py
[x] (only when updating dataset) Ran annotation.import to completion
[ ] (only when updating dataset) Updated Surface Dice tolerances in labels.py (execute sample_segmentations.py, and after that compute_tolerances.py. Then put the new values in. Do not re-use sampled segmentations from prior dataset versions!)