add user guide parallelization
setup
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.
Comments of the PR
Move canny from filter to feature
remove auto added __author__ in __init__.py file
ENH: Simplify marching_cubes for maintainability.

This does not change execution time, but the entire algorithm
is much simpler to read and understand without the branching
Cython code paths for anisotropic inputs. Memory usage decreases
a minor amount.
fix wrong version number
update api_changes
Added gitwash as an option on the makefile.
Updated the gitwash build.
Some minor documentation enhancements.
Merge pull request #1112 from pelson/docs_tidy

DOC: Minor documentation enhancements.
making in-place addition modification suggested in issue #1089
fix import inside documentation and update TODO
fix import in filter.__init__
move import to avoid infinte recursion (filter import peak that import feature that import filter)
Canny is now deprecated and will be in api_changes in v0.13