API: kdeplot fails with NaNs

Test cases for kde with missing vals

Drop na values before creating kde

Add to the release notes
Merge pull request #8196 from onesandzeroes/kde-na

API: kdeplot fails with NaNs.
counting sort instead of np.argsort in left outer join
BUG: GroupBy.count() with float32 data type does not exclude nan
Merge pull request #8171 from behzadnouri/count-f32

BUG: GroupBy.count() with float32 data type does not exclude nan
Merge pull request #8172 from behzadnouri/lj-cnt-sort

counting sort instead of np.argsort in left outer join
BUG: barplot with NaNs
DOC: Table about how plots handle missing data.
Merge pull request #8177 from TomAugspurger/barplot-NaN

BUG: barplot with NaNs
BUG: Fix Grouper with multi-level index and frequency (GH7885)
BUG: Fix mismatched logic error in compatibility check
Merge pull request #8203 from jtratner/fix_openpyxl_compat_check

BUG: Fix mismatched logic error in compatibility check
Merge branch 'Fix-GH7885' of https://github.com/jmorris0x0/pandas into jmorris0x0-Fix-GH7885
COMPAT:  dtype on windows related to GH8172
WIP: TimedeltaIndex and Timedelta scalar support (GH3009)
add tdi to .dt
fixed py3 internals coercion