Raise error in certain unimplemented aggregation cases.
BUG: column name conflict & as_index=False breaks groupby ops
ENH: Add ISO3 ctry codes and error arg. Fix tests, warn/exception logic #8482
BUG: coerce Categorical in record array creation (GH8626)
BUG: Categorical not created properly with to_frame() from Series (GH8626)
BUG: handle astype with passed pd.Categorical (GH8626)
Merge pull request #8652 from jreback/to_cat

BUG: various categorical fixes (GH8626)
Merge pull request #8592 from staple/reduce

ENH: Raise error in certain unhandled _reduce cases.
Merge pull request #8585 from behzadnouri/in-axis

BUG: column name conflict & as_index=False breaks groupby ops
Merge branch 'wbISO3' of https://github.com/jnmclarty/pandas into jnmclarty-wbISO3

Conflicts:
	doc/source/whatsnew/v0.15.1.txt
BUG: Do not overwrite index name with plot
Merge pull request #8541 from TomAugspurger/plot-label-index-name

BUG: Plot with ``label`` would overwrite index name
DOC: v0.15.1.txt corrections
BUG: fix concat to work with more iterables (GH8645)
BUG: Bug in setitem with empty indexer and unwanted coercion of dtypes (GH8669)
Merge pull request #8668 from waveform80/deque-concat

BUG: fix concat to work with more iterables (GH8645)
Merge pull request #8671 from jreback/coerce

BUG: Bug in setitem with empty indexer and unwanted coercion of dtypes (GH8669)
BUG: years-only in date_range uses current date (GH6961)
Merge pull request #8672 from rosnfeld/issue_6961

BUG: years-only in date_range uses current date (GH6961)
ENH: Series.str.split can return a DataFrame instead of Series of lists
TST: fix up for 32-bit indexers w.r.t. (GH8669)
Merge pull request #8675 from pydata/setitem

TST: fix up for 32-bit indexers w.r.t. (GH8669)