Refactor to allow matrix structure in covariance matrices to be exploited
Improve handling of linear algebra issues; add options to fine tune iterations
Fixed typo NOne -> None
Minor renaming and docstring edits
Minor typographical changes
Minor docstring and naming changes, ready to merge
STY: Pep-8
BUG: Fix refactor victim
Merge pull request #1657 from jseabold/summary2-bug

BUG: Fix refactor victim.
ENH: avoid hard-listed bandwidths -- use present dictionary (+typos fixed)
Merge pull request #1643 from kshedden/gee-linalg-refactor2

REF: Allow matrix structure in covariance matrices to be exploited
Merge pull request #1671 from yarikoptic/enh/typos_and_bandwidths

DOC/ENH: avoid hard-listed bandwidths -- use present dictionary (+typos fixed)