adjust timezone when adding date offsets for DST. fixes #5175
BUG: Fix for to_excel +/- infinity

Previously, a negative sign was being prepended to positive infinite
values and was absent for negative infinity. (GH6812)

TST: assert_almost_equals() checks +/- infinity

The existing ``test_inf_roundtrip`` should have caught this bug, but
the underlying ``assert_almost_equal`` was not checking that the two
given values were both positive or negative.
BUG/API: Previously an enlargement with a mixed-dtype frame would act unlike .append which will preserve dtypes (related GH2578, GH8176)
Merge pull request #8176 from jreback/expand

BUG/API: Previously an enlargement with a mixed-dtype frame would act unlike append (related GH2578)
Merge branch 'excel-infinity-fix' of https://github.com/maxchang/pandas into maxchang-excel-infinity-fix
Merge branch 'dst-date-offset' of https://github.com/adamgreenhall/pandas into adamgreenhall-dst-date-offset

Conflicts:
	doc/source/v0.15.0.txt
DOC: added release note, this fixes #8173
Merge pull request #8179 from mortada/nth_values_notes

DOC: added release note, this fixes #8173
BUG: barplot with NaNs
DOC: Table about how plots handle missing data.