MAINT: remove most references to symeig and move lobpcg benchmarks out of the test directory
MAINT: remove the rest of the symeig references
DOC: move docs from __init__.py to the lobpcg docstring
BENCH: lobpcg vs. eigh mikota pair benchmark now works
BENCH: let the preconditioner do mat-mat explicitly, not just mat-vec
BENCH: resurrect another lobpcg benchmark
MAINT: remove unused imports
MAINT: change variable names that used incorrect terminology
MAINT: remove the '__main__' section and the X.txt file from lobpcg
TST: the '__main__' lobpcg.py code is now a real test
BUG: correlate was extremely slow when in2.size > in1.size
Adds default params to pdfs of multivariate_norm

Adds default params to pdf and logpdf to match
`norm` and the documentation.
STY: PEP8 fixes for signaltools test (partially autopep8)
TST: Add a test for swapping of inputs
when in2 is bigger than in1, test reversal in 3 dimensions and complex conjugation
WHT: signal: more pep8 in tests
Merge pull request #3664 from pr-3664

BUG: signal: correlate was extremely slow when in2.size > in1.size

This change swaps the inputs if the first is smaller, but then reverses
and conjugates the output to undo the effects of the reversal.
BUG: signal.welch: ensure floating point dtype regardless of input dtype

Fixes gh-3655.
DOC: adding differential_evolution function to 0.15 release notes
Merge pull request #3671 from andyfaff/diffev-releasenotes

DOC: adding differential_evolution function to 0.15 release notes
Merge pull request #3599 from argriffing/remove-symeig

MAINT: symeig removal