Do not allow view_as_* to return copies (closes #866)
Take a softer approach and raise a warning when a non-contiguous input is provided
Update view_as_windows docstring
Fix typo in docstring
Update viewer example to use plugin outputs
Update lineprofile examples to use returned output
Update plugin class doc example to use output
add step 4: review
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
Stefan's comments
Add Juan's comments
Make another pass through contributing guidelines
Merge pull request #3 from stefanv/contributing

Make another pass through contributing guidelines
fix typo
Merge pull request #982 from sciunto/contributing

CONTRIBUTING: add step 4: review
Update Canny examples
Use Astropy by default if possible
Added entry for Astropy in DEPENDS.txt