PERF faster head, tail and size groupby methods
TST: correctly predict locale setability

Don't join the lang and encoding when performing the trial set, because

    locale.setlocale(locale.LC_ALL, ('it_CH', 'utf-8'))

succeeds, but

    locale.setlocale(locale.LC_ALL, 'it_CH.utf-8')

throws locale.Error.
Merge pull request #5538 from neirbowj/fbsd_failing_tests

TST: correctly predict locale setability
TST: fix cumcount test on 32-bit env
Merge pull request #5540 from gdraps/cumcount-test-fix

TST: fix cumcount test on 32-bit env
BUG: Bug in delitem on a Series (GH5542)
Merge pull request #5544 from jreback/series_del

BUG: Bug in delitem on a Series (GH5542)
DOC: Fixing a good number of spelling mistakes in 0.13 release notes
DOC: replace _prop_attributes with __finalize__()
DOC: mention new to_clipboard/paste into excel capability
Merge pull request #5548 from y-p/doc_toclipboard

DOC: mention new to_clipboard/paste into excel capability in release docs
Merge pull request #5547 from aldanor/patch-1

DOC: Fixing a good number of spelling mistakes in 0.13 release notes
TST more coverage for groupby head and tail
Merge pull request #5533 from hayd/groupby_head_tail

PERF faster head, tail and size groupby methods
BUG: Bug fix in apply when using custom function and objects are not mutated (GH5545)
Merge pull request #5554 from jreback/apply_bug

BUG: Bug fix in apply when using custom function and objects are not mutated (GH5545)
BUG: Bug in selecting from a non-unique index with loc (GH5553)
Merge pull request #5555 from jreback/loc_bug

BUG: Bug in selecting from a non-unique index with loc (GH5553)
BUG: repr of series fails in the presence of a Float64Index that is not monotonic (GH5557)
DOC add cumcount ascending kwarg