Merge pull request #1612 from josef-pkt/fix_negbin_exposure_1611

BUG/ENH Fix negbin exposure #1611
DOC: Add docs for Nile dataset.
DOC: Remove generated docs from version control
DOC: Use literal block for NOTE section
DOC: Pep-8
DOC: Use literal block for all NOTE sections
MAINT: Allow dataset docs to be automatically generated
Merge pull request #1619 from jseabold/dataset-cleanup

MAINT: Dataset docs cleanup and automatic build of docs
DOC: typo, "interecept"
Merge pull request #1630 from larsmans/interecept

DOC: typo, "interecept"
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
Fix rebase conflict
STY: Pep-8
BUG: Fix refactor victim
Merge pull request #1657 from jseabold/summary2-bug

BUG: Fix refactor victim.