Set the unused portion of the image to 0
Implement a mode enum
Update docstring
Change 'trim' to 'crop'
Add test for adapthist modes
Switch to HSV, refactor equalize_adapthist, fix #757, cleanup docstring
Update adapthist tests, add test for alpha channel and rgb mode handling.
Fix failing tests and turn module level testing back ony
Start removing optional edge pixel handling
Add tests for intensity_range and rename parameter
Fix handling of border pixels and update tests
Refactor to use np.pad, naming changes, update test.
Remove unused deprecation import.
Merge pull request #893 from blink1073/fix-adapthist-757

Add option for Adaptive Histogram border pixel handling.