BLD: erase local ipython_directive
BLD: pull in latest ipython_directive from ipython 0355d3d
BLD: ipython_directive, add back okexcept
BLD: ipython_directive, enforce tight layout for mpl plots
BLD: ipython_directive, cython magic fix
BLD: make io.rst utf8-safe GH5142 GH5926
BLD: ipython_directive, decode ipython output as utf8+replace
BUG: don't lose dtypes when concatenating empty array-likes
Merge pull request #5742 from immerrr/dont-lose-dtype-concatenating-empty-arraylikes

BUG: don't lose dtypes when concatenating empty array-likes
Merge pull request #5925 from y-p/PR_rebase_ipython_directive

Rebase ipython_directive on top of recent ipython updated version
BUG: Raise ValueError with incompatible version of numexpr installed
COMPAT: Require numexpr v2.0 or above.

Otherwise ignore it (issue with API change pre-2.0)
Add basic test for min elements with or without numexpr
switch to using _USE_NUMEXPR
Fix overwriting import alias
CLN: Use single variable to check numexpr allowed

in pandas/computation/__init__.py vs. previous behavior of different
modules checking in different ways.
Fix ne skip test check
Fix extra numexpr calls