ENH: Add dtype parameter to linspace and logspace functions.

Many NumPy functions such as arange allow users to define the dtype of the
returned type with a dtype parameter.  This adds this same functionality
to the logspace and linspace functions.
ENH: percentile function with additional parameters and vecorization

The percentile function was enhanced by adding limit and interpolation
parameters to give it similar functionality to SciPy's stats.scoreatpercentile
function.  In addition the function was vecorized along q and rewritten to
use the partition method for better performance.
MAINT: cleaning up percentile function.
DOC: changes to scoreatpercentile docstring, doc test now passes
TST: additional test for percentile
DOC: Make documentation of nansum current with 1.9.

Simply state that Numpy versions < 1.9 returned nan instead of zero
for the sum of empty slices.
BUG: use correct type for hash values

As of Python 3.2 hash values are of type Py_hash_t. Previous versions use C long.
Merge pull request #3747 from cgohlke/py_hash_t

Fix issue #3743: Hash changed signature in Python 3.3
Merge pull request #3746 from charris/fix-nansum-documentation

DOC: Make documentation of nansum current with 1.9.
DOC: improve __numpy_ufunc__ documentation

Cross-reference it from Ufunc documentation and mention the version it
was added.
MAINT: changed 'closest' interpolation to 'nearest'
TST: note on overwrite_input parameter in percentile

* added note that `overwrite_input` has not effect when `a` is not
  an array in the percentile function.
* added unit test to verify that no error is raised when `a` is not
  an array and `overwrite_input` is True.
Merge pull request #3482 from jjhelmus/linspace_enh

ENH: Add dtype parameter to linspace and logspace functions.
MAINT: update release scripts for building OS X binaries.

Works with Python 3.x now that bdist_mpkg is ported (thanks @matthew-brett).
BUG: Fix issue with PR #3491

Don't convert unicode string to ascii string before getting byte length.
Also, get length of non string type as ascii or unicode depending on
output string type.
Merge pull request #3765 from charris/forward-port-3761

BUG: Fix issue with PR #3491
Merge pull request #3658 from jjhelmus/percentile_enh_new

ENH: percentile function with additional parameters and vectorization
Merge pull request #3752 from pv/doc-some-xref

DOC: improve __numpy_ufunc__ documentation