BUG: GH3448  Unordered time series selection was misbehaving when using label slicing
Merge pull request #3452 from jreback/GH3448

BUG: GH3448  Unordered time series selection was misbehaving when using label slicing
TST: to_csv respects cols= reordering GH3454/7
BUG: to_csv handles cols= reordering,dupe cols GH3454/7
DOC: update RELEASE.rst

PTF