ENH: allow read_excel to accept URLs (GH6809)
TST/CLN: centralize module check funcs
BUG: df.reset_index loses tz
BUG: offsets.apply may return datetime
Merge pull request #7533 from sinhrks/resetindex

BUG: df.reset_index loses tz
Merge pull request #7451 from sinhrks/skiptest

TST/CLN: centralize module check funcs
Merge pull request #7502 from sinhrks/offsetret

BUG: offsets.apply may return datetime
DOC: Use correct, non-deprecated arg name
TST: dtype test fixes for GH7533
TST: some yahoo options tests missing network decorator
Merge pull request #7549 from cpcloud/fix-network-error-yahoo-options

TST: some yahoo options tests missing network decorator
DOC: correct relase note
Merge pull request #7550 from sinhrks/rn_fix

DOC: correct relase note
Merge pull request #7545 from neirbowj/frame_to_excel_docstring

DOC: Use correct, non-deprecated arg name
Merge pull request #7531 from dsm054/excel-via-url

WIP/ENH: allow read_excel to accept URLs (GH6809)
BUG: Bug in setitem with list-of-lists and single vs mixed types (GH7551)
Merge pull request #7552 from jreback/iloc

BUG: Bug in setitem with list-of-lists and single vs mixed types (GH7551)
WIP: categoricals as an internal CategoricalBlock GH5313
Categorical: add new constructor mode

Catgoricals: implement min/max/sort
CLN: integrate JanSchulz changes
     change _value_pointer back to labels

BUG: fix up PeriodIndex formatting/printing
API: Categorical sort api backwarks - now conform to Series interface (order returns a copy, sort is inplace)

ENH: delegate _reduction and ops from Series to the categorical
     to support min/max and raise TypeError on other ops (numerical) and reduction