BUG: Fixed passing keep_default_na=False when na_values=None (GH4318)
DOC: add new sections na_values, infinity to read_csv docs
Merge pull request #4374 from jreback/GH4318

BUG: Fixed passing keep_default_na=False when na_values=None (GH4318)
BUG:  Fixed bug with values raising an error on a DataFrame with duplicate columns and mixed
      dtypes, surfaced in (GH4377)

BUG:  Fixed bug with duplicate columns and type conversion in read_json when
      orient='split' (GH4377)
Merge pull request #4399 from certik/docs

DOC: typo fix
Merge pull request #4388 from jreback/GH4377

BUG: fixes for GH4377
BUG: Fix .iat indexing with a PeriodIndex GH4390
     Series.get with negative indexers returns the same as []
Merge pull request #4394 from jreback/pi_iat

BUG: Fix .iat indexing with a PeriodIndex GH4390
BUG: fix period index object instantiation when joining with self
Merge pull request #4379 from cpcloud/self-join-index-is-same

BUG: fix period index object instantiation when joining with self
Fixed issue #4345.
Merge pull request #4360 from nfoti/master

Fix issue #4345: graphics test failure
Fix an issue with the csv cparser when usecols is used
Merge pull request #4406 from tr11/fix_csv_parser_dtypes

BUG: Fix an issue with the csv cparser when usecols is used
BUG: Fix an issue in merging blocks where the resulting DataFrame had partially set _ref_locs (GH4403)
Merge pull request #4410 from jreback/df_rename

BUG: Fix an issue in merging blocks where the resulting DataFrame had partially set _ref_locs
BUG/VIS: fix Series.hist so that users can create hist subplots without the mpl API
ENH: add more informative error message when dupe style and color args are given
Merge pull request #4414 from cpcloud/fix-hist-subplots

BUG/VIS: fix Series.hist so that users can create hist subplots without the mpl API
FIX: revert docs and fix for py3 compat