DOC: Fix typos, punctuation, and grammar.
MAINT: Grammar and style corrections to whatisnumpy.rst.
Merge pull request #4756 from charris/gh-4688

Extend gh-4688 style improvements to whatisnumpy.rst.
BUG: Don't let meshgrid ignore unknown kwargs. Fixes #4755.
Merge pull request #4758 from mforbes/issue_4755

BUG: Don't let meshgrid ignore unknown kwargs. Fixes #4755.
MAINT: fix a few harmless compiler warnings
Merge pull request #4759 from juliantaylor/warning-fix

MAINT: fix a few harmless compiler warnings
MAINT: Removed code emulating keepdims in cov
Merge pull request #4761 from dfreese/maint/keepdimsincov

MAINT: Removed code emulating keepdims in cov
TST: fix random failing histogram test

histogramdd rounds by decimal=6 so the random numbers may not be
outliers if they are below 1. + 1e6
Merge pull request #4762 from juliantaylor/hist-test

TST: fix random failing histogram test