Flake and PEP8 label.py.
Add a max_width attribute to Label objects.
PEP8 text_box_overlay.py
Add a max_text_width attribute to TextBoxOverlay.
Merge branch 'master' into feature/max-width-labels
Added the improvement to the changelog.
Merge pull request #128 from enthought/feature/max-width-labels

Add max_width to the Label class