VIS: plot with `use_index=False` shouldn't plot the index name

Add test case

Add check for use_index before setting label

Add to release notes

Add test case for barplot

Add checks for use_index in bar plot

Missed merge conflict marker
ENH: serialization of categorical to HDF5 (GH7621)
Merge pull request #8812 from onesandzeroes/plotlabel

VIS: plot with `use_index=False` shouldn't plot the index name
BLD: fix odd usage of cython imports, xref (GH8602)
Merge pull request #8793 from jreback/cat_hdf

ENH: serialization of categorical to HDF5 (GH7621)
DOC: v0.15.2 edits
Add test case for mixed type stacking
Used wrong var name in the assert
Method to swap levels assuming ints are level numbers
Fix _stack_multi_columns to deal with mixed strs/ints
Extra testcases
Add fix to the release notes
Convert to label before swaplevel if possible
Revert "Method to swap levels assuming ints are level numbers"

This reverts commit 61f96fd3cb23cda9f9c7a6837b145ebd247a55cc.
More test cases
Use _convert_level_number() to sort columns