Merge pull request #2917 from dlax/minimize_scalar-tol

BUG: optimize: warn that bounded method in minimize_scalar does no support relative tolerance
MAINT: remove LyX files from stats tutorial docs
BUG: io/wavfile: safer writing directly from buffer

Fixes gh-2928
reduced number of test failure cases for hyperu
ENH: interpolate: remove fill_value completely from PPoly

Instead, extrapolate based on the outermost intervals.  This makes
integrals, derivatives, antiderivatives, and root finding robust
operations.
Merge pull request #2933 from pv/wavfile-buf

BUG: io/wavfile: safer writing directly from buffer
Merge pull request #2916 from pv/ufunc-fix

BUG: sparse: minor bugfixes
Merge pull request #2920 from ClemensFMN/db_correction

DOC: signal: corrected dB in amplitude response examples
BUG: spatial.distance: always convert to float in sqeuclidean

Integers are subject to silent wraparound in the subtraction and
squaring operations, as pointed out by @jakevdp. Some unnecessary
copying may occur, but any call where both arguments are float
arrays still only allocates a single temporary array.
Included a call to set_iprint in TestODR.test_explicit
Made sure griddata docs are clear that it is D-dimensional and there are n points. It was ambiguous.
Merge pull request #2936 from BenFrantzDale/fix-griddata-docs

DOC: sparse: Made sure griddata docs are clear
BUG: sparse: fix crashes/wrong results in broadcasting multiply

The dia_matrices used to broadcast column/row vector elementwise
multiplications should be square.  The matrices are passed directly to
the internal _mul_* methods, which make no data size or shape checks, so
wrong size gives wrong results or segfaults with no warnings.
BUG: interpolate/_ppoly: sort roots to avoid reporting duplicates
ENH: interpolate: allow extrapolation in PPoly
Fixed typo
Merge pull request #2910 from rgommers/issue-2842-qz

TST: linalg: qz test fails for complex64, so lower test tolerance.
TST: fftpack: remove check of successful overwrite

The overwrite may not happen if f2py decides to make copies e.g. due to
aligment. The purpose of the test is to check only that no spurious
overwrites occur.
Merge pull request #2941 from pv/fft-no-overwrite-assert

TST: fftpack: remove check of successful overwrite
Merge pull request #2924 from FabricioS/future_division_odr

BUG: odr: fixed integer division in indices