ENH: added functionality nanmedian to numpy

Implemented a nanmedian and associated tests as an
extension of np.median to complement the other
nanfunctions

Added negative values to the unit tests

Cleaned up documentation of nanmedian
Fix for #4655: Make fftpack._raw_fft threadsafe
MAINT: Remove deprecated importall.

The importall function was the only function in the numpytest.py
file, so remove the whole file.
DOC: Update the release notes.

Remove duplicated "New Features" heading.
Note removal of numpytesting.py file containing importall function.
Add comments to clarify cache handling in _raw_fft
MAINT:Ignore boolean '-' deprecation warnings in nosetester.py

This allows numpy 1.9 testing to be used with current scipy
without flooding the output with deprecation warnings.

The deprecation warnings are currently issued for both the
subtract and negative operators when used with booleans.
Merge pull request #4307 from dfreese/feature/nanmedian

ENH: added functionality nanmedian to numpy
Added regression tests for #4655
DOC: update 1.9.0-notes.
BUG: Add @DEFINE_NPY_RELAXED_STRIDES_CHECKING@ to _numpyconfig.h.in.

The entry is needed for Bento builds to correctly configure numpy.
Merge pull request #4682 from charris/fix-_numpyconfig.h.in

BUG: Add @DEFINE_NPY_RELAXED_STRIDES_CHECKING@ to _numpyconfig.h.in.
Make TestFFTThreadSafe tests Py3-compatible
Merge pull request #4656 from foogod/master

Fix for #4655: Make fftpack._raw_fft threadsafe
Merge pull request #4680 from charris/pre-1.9.x-branch

Pre 1.9.x branch