ENH: improve nanmedian performance

remove unnecessary copy, an unnecessary sort and use inplace median on
the compressed copy.
Fix "imresize does not work with size = int"

Solution from http://mail.scipy.org/pipermail/scipy-dev/2010-July/015132.html

Also adds test_imresize4.
Add scipy.stats.sigmaclip to the html docs
Merge pull request #3357 from nh2/fix-imresize-int

Fix "imresize does not work with size = int"
Merge pull request #3371 from cdeil/docs_sigmaclip

scipy.stats.sigmaclip doesn't appear in the html docs.
ENH: interpolate: restore duck-typed array_like support in RegularGridInterpolator
Merge pull request #3323 from pr-3323

ENH: interpolate: add interpn and RegularGridInterpolator

Implemented a new class RegularGridInterpolator for efficient linear and
nearest-neighbour interpolation on regular (possibly unevenly spaced)
grids in arbitrary dimensions.

The existing ND-interpolators perform a triangulation of the input
points with becomes unfeasible with medium (~8) dimensions.  There, by
taking advantage of the regular grid structure, the interpolation can be
sped up quite a bit.

Another advantage of this class is that it accepts anthing that can be
appropriately indexed as values parameter, meaning that it is possible
to use this interpolation object for interpolation of disk-based data
sets (netCDF, pytables, ...).

This PR also adds a simpler function `interpn` for regular grid data
interpolation.
Merge pull request #3335 from juliantaylor/nanmedian

ENH: improve nanmedian performance
DOC: list BLAS functions by level

[ci skip]
Merge pull request #3380 from ev-br/blas_docs

DOC: list BLAS functions by level
ENH: sparse/dsolve: use tp_getset instead of getattr in _superluobject.c

This is a cleaner solution.
ENH: sparse/dsolve: make the L and U factors of splu and spilu accessible from Python
ENH: sparse/dsolve: rename the superlu object, and expose and document it properly
DOC: sparse/dsolve: update versionadded