Added support for different illuminants.
Added new tests. The support for a wider range of illuminants is now tested.
Added tests for the new functionality.
Undone change in skimage/__init__.py.
The format strings were updated to include numbers.
Corrected code to conform to Python coding conventions (PEP 8).

Added test code for handling exceptions.

Corrected test code to use the full path to the test data.
Added Stephan comments.

Syntax is now checked using `flake8`.
Removed the print statements from the test code.
Incorporated Stefan's comments.
Update build requirements and documentation
Reorganized dependencies in DEPENDS.txt.
Fix install_requires string formatting
Fix python 3 unicode error
Remove unicode decode
Fix python3.3+ builds
Look for  version instead of  version
Add description for networkx optional requirment
Add stop_probability to RANSAC
Add sanity checks for input parameters
Allow modification of LineTool handle style