BUG: Bug in multi-index slicing with incomplete indexers (GH7399)
TST7337: Disallow use of dateutil tzfile objects whose filename contains '.tar.gz'.
TST7337: Fix test failures on windows.

Avoid constructing dateutil timezones explicitly because of filename issue.
Use dateutil.tz.tzutc() to construct UTC timezone instead of
dateutil.tz.gettz('UTC')
Update docs to reflect this.
Tidy up examples in the timezones section of the docs.
BUG: Bug in multi-index slicing with a step in a sliced level (GH7400)
Add test for conversion between dateutil.tz.tzutc() and dateutil.tz.gettz('UTC')
Merge pull request #7404 from jreback/mi_indexing

BUG: mi indexing bugs (GH7399,GH7400)
BUG/OUTPUT: fix repring of MI nat

Fix neg indexers in datetimeindex
Merge pull request #7362 from ahlmss/windows_tests

TST7337: Fix test failures on windows.
Merge pull request #7410 from cpcloud/nat-index-first-take-7406

BUG: fix repring of nat multiindex and fix neg indexing in datetimeindex