ENH: scipy.spatial.distance: use BLAS and waste less memory

This module was using np.linalg.norm instead of the SciPy version,
which switches to BLAS when appropriate.

The change to sqeuclidean makes it four times faster for length-1e5
random vectors using NumPy 1.6.2 linked against ATLAS 3.8.4:

>>> %timeit ((u - v) ** 2).sum()
1000 loops, best of 3: 2.01 ms per loop
>>> %timeit u_v = u - v; np.dot(u_v, u_v)
1000 loops, best of 3: 552 us per loop
small changes
enhanced signal tutorial
DOC: rename the shapes for randint distribution.

Make them match the numpy random_integer generator's.
DOC: rename the shape parameter for Von Mises distribution.

Now it matches the numpy one.
further signal tutorial enhancements
DOC: change the shape name for vonmises in stats tutorial
Fixed integer division in indices.
added detrend and spectral estimation
Fixed integer division in indices.
MAINT: remove LyX files from stats tutorial docs
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
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.
Fixed typo
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
Merge pull request #2925 from ClemensFMN/signal_tut

DOC: Enhance signal tutorial
TST: fix spurious test failure in linalg.  Closes gh-2945.