DOC: stats: Remove the trailing '_' from the reference to 'levene'.
DOC: stats: Use a more conventional description of the default value for 'moments' in the continuous distribution docstring.
DOC: stats: Fix a bad indent in the histogram docstring.
DOC: stats: Tweak the layout of the PDF function in the ncf docstring.
DOC: stats: Fix bad indent in the relfreq docstring.
Merge pull request #3894 from WarrenWeckesser/doc-stats

DOC: stats: Assorted docstring edits.