BUG: format label for inf in cut with a str directly

TST: disable sparse test on pow on win32

TST: skip msgpack testing in 2.6 for datetimes with tz

TST: dtype test compat in io/tests/test_excel.py
Merge pull request #5574 from pydata/win32_fix2

Win32 fix2
DOC: Series.reorder_level() can take names
DOC/TST reorder_levels takes names