Update viewer example to use plugin outputs
Update lineprofile examples to use returned output
Update plugin class doc example to use output
DOC: Clarify UMFPACK warning; use if statements instead of assert
FIX: Shortcut output or catch trivial cases in random_walker

Also:
* New tests to cover these new checks
* Improvements to docstrings and user warnings
* Generalize handling of `sampling` in accordance with docstring
* Some extra whitespace to improve readability
TST: Add unit test for length-2 spacing with rank-2 input
Update Canny examples
Fix cython compilation warnings
Fix custom six issue in scipy 0.14 on python 3.4
Merge pull request #998 from ahojnnes/python34

Fix cython warnings and "six" under python 3.4
Always interpret provided shapes as int. Add a note on using output_shape for color images.
Add unit test to catch non-integer output shape bug
STY: More elegant and maintainable style per code review
FEAT: Shared function for safe int casting
Remove check for non-numeric values in spacing.
Merge pull request #984 from JDWarner/randwalk_trivialcheck

Random Walker improvements and checks for trivial cases
Convert name to _safe_as_int, output np.int64, expand Examples
FIX: Remove unnecessary .transpose introduced in PR #984
Merge pull request #1001 from JDWarner/rw_transpose

FIX: Remove unnecessary .transpose introduced in PR #984
failUnless -> assertTrue