TST: run clipboard tests explicitly
CLN: Specialize assert_(np.array_equal(...))

Work on #6175. Work in progress. One more commit needed to finish; splitting to keep reasonably sized.

* Changes assert_numpy_array_equals to assert_numpy_array_equal, for consistency with other methods. (API change of recently-added function)
* Changes instances of assert_(np.array_equal(A,B)) to assert_numpy_array_equal(A,B)
* Update release.rst to reflect work on #6175
Merge pull request #6368 from bwignall/assert_6175_arrayequal_1

CLN: Specialize assert_(np.array_equal(...))
CLN: Specialize assert_(np.array_equal(...))

Work on #6175. This is the second half of the work started in #6368.
BUG: DataFrame.shift with axis=1 was raising (GH6371)
Merge pull request #6373 from jreback/df_shift

BUG: DataFrame.shift with axis=1 was raising (GH6371)
Merge branch 'explicit-cb' of https://github.com/cpcloud/pandas into cpcloud-explicit-cb

Conflicts:
	doc/source/release.rst
PERF: fix series slice indexing performance
API/BUG: reindex_like not passing copy/limit kwargs thru
Merge pull request #6372 from immerrr/fix-perf-for-series-slices

PERF: fix performance for series slices (even more)
Merge pull request #6374 from bwignall/assert_6175_arrayequal_2

CLN: Specialize assert_(np.array_equal(...))
PERF: take the fast path on a reindex when reindexers are identical
checkin of percentage rank