BUG: Fixed a bug in DataFrame/Panel cache insertion and subsequent indexing GH4939
Merge pull request #4942 from jreback/index_cache

BUG: Fixed a bug in DataFrame/Panel cache insertion and subsequent indexing GH4939
BUG: Fix FrozenNDArray & FrozenList string methods

Plus basic tests (i.e., "Hey! If you pass me unicode I don't fail -
yay!")
Merge pull request #4929 from jtratner/fix-repr-on-FrozenNDArray-and-FrozenList

BUG: Fix FrozenNDArray & FrozenList string methods