BUG: Bug in inplace operations with column sub-selections on the lhs (GH8511)
Merge pull request #8520 from jreback/indexing

BUG: Bug in inplace operations with column sub-selections on the lhs (GH8511)
BUG: fix CategoricalBlock pickling

* TST: add categorical frame and series to generate_legacy_pickles

* TST: generate pickle for 0.15.0
COMPAT: ensure Categorical reads v0.14.1 pickles correctly (doesn't work yet)
COMPAT: Category pickle compat