BUG: sparse/sparsetools: catch exceptions in std::vector allocation
ENH: sparse/sparsetools: release GIL in sparsetools routines
TST: sparse: add test running sparsetools code in parallel threads
BLD: fix Qhull build issue with MinGW-w64.  Closes gh-3237.

Thanks to Carl Kleffner.
BUG: special: erfcinv with small arguments loses precision.

Change the implementation of special.erfcinv from

    ndtri((2-y)/2.0)/sqrt(2)

to

    -ndtri(0.5*y)/sqrt(2)

The subtraction caused a loss of precision for small argments, and
anything less than about 1e-16 returned inf.

The boost test data file erfc_inv_big_data.txt
(in special/tests/data/boost/erfc_inv_big_data_ipp) was split into
two files: erfc_inv_big_data1.txt and erfc_inv_big_data2.txt,
Only erfc_inv_big_data2.txt contains useful test data; tests with
this file are now enabled.

Regenerated boost.npz, and fixed the name of the 'ellipkm1'
data set in the code that runs the boost data tests.
ENH: make interp2d accept unsorted arrays for interpolation.

Change prompted by terrible error message in gh-3489.
Merge pull request #3547 from WarrenWeckesser/special-erfcinv

BUG: special: erfcinv with small arguments loses precision.
Merge pull request #3565 from rgommers/interp2d-unsorted

ENH: interpolate: make interp2d.__call__ accept unsorted arrays for interpolation.
ENH: Fix issues in scipy.misc.logsumexp (issue #3515)

See ticket #3515. This commit adds the following features to logsumexp:
  * `axis` can be a tuple of ints (if NumPy >= 1.7.0)
  * `keepdims` added, works similarly as `keepdims` in `numpy.sum`
Also, infinite values are handled properly, returning positive or
negative infinity as approriate instead of NaN.
TST: Add a few unit tests for the bug fixes in scipy.misc.logsumexp
ENH: misc: move slow version check to global variable

Also ignore warning in test
Merge pull request #3518 from pr-3518s

ENH: misc: logsumexp improvements

- axis can be a tuple of ints
- keepdims added, works similarly as keepdims in numpy.sum

Also, infinite values are handled properly, returning positive or negative
infinity as approriate instead of NaN.
Merge pull request #3477 from pv/sparse-threads

ENH: sparse: release GIL in sparsetools routines
STY/MAINT: trim dead code, reduce compiler warnings

Removed the Cephes rational arithmetic functions (euclid.c), which were
entirely unused.

Also dead statements, non-prototype (K&R) declarations.

Reduces warning log by exactly 300 lines on my box.
Merge pull request #3537 from larsmans/warnings

STY: reduce number of C compiler warnings
BUG: io/netcdf: Call mmap only once to prevent too many open files
TST: io/netcdf: remove unnecessary use of test generators

Test generators are best used only for iterating over parameter sets,
and otherwise best avoided.
BUG: io/netcdf: clean up code a bit
Merge pull request #3429 from pr-3429

BUG: io/netcdf: use only a single mmap in netcdf

Using a separate mmap for each access of each varible can cause running
out of file descriptors on some platforms.  Address this by using a
single mmap covering the whole file.
Merge pull request #3484 from rgommers/mingw64-qhull

BLD: fix Qhull build issue with MinGW-w64.

Closes gh-3237.