Merge pull request #7133 from toddrjen/sem

ENH: Implement "standard error of the mean"
BUG: Bug in .loc with a list of indexers on a single-multi index level (that is not nested) (GH7349)
Merge pull request #7350 from jreback/mi_index

BUG: Bug in .loc with a list of indexers on a single-multi index level (that is not nested) GH7349
BUG: Revisit Index.delete preserves freq
DOC: minor v0.14.1 editing
Merge pull request #7320 from sinhrks/delete

BUG: Revisit Index.delete preserves freq
make nanops._maybe_null_out work with complex numbers ( issue #7353 )
support axis=None for nanmedian ( issue #7352 )
make nanops work when ndim==1 and axis==0 ( issue #7354 )
Make nanops._has_infs work for additional dtypes and multidimensional arrays ( issue #7357 )
add tests for nanops
minor nanops pep8 fixes