ENH: Add functions for creating dataframes with NaNs
Merge pull request #6465 from jreback/infer_freq2

COMPAT: infer_freq compat on passing an Index of strings (GH6463)
BUG: split should respect maxsplit when no pat is given
Merge pull request #6467 from cpcloud/str-pat-n-fix-6466

BUG: split should respect maxsplit when no pat is given
DOC: release notes for #6466
Merge pull request #6422 from jseabold/make-missing

ENH: Add functions for creating dataframes with NaNs
ENH: initial commit for parallel support (GH5751)
ENH: dataframe.apply working in parallel!
ENH: add vb_suite for parallel
     default for config option is None