REL: Release 1.9.0b1

Point release notes to doc/release/1.9.0-notes.rst
Set LOG_START to 'v1.8.1'
Set LOG_END to 'maintenance/1.9.x'
Set raise_warnings to "release" in NoseTester constructor.
Merge pull request #4849 from juliantaylor/master

merge master into 1.9 branch
Merge pull request #4871 from juliantaylor/linspace-version-doc

DOC: add version added tag to new linspace dtype argument
BUG: add missing elementsize alignment check for simd reductions

e.g. doubles are only aligned to 4 bytes on i386 so one cannot peel them
to 16 byte alignment.
Closes gh-4853
BUG: Use `np.where` in np.triu/np.tril, fixes #4859

Replaces the current method to zero items, from multiplication to
using `np.where`.
DOC: fix a typo and use TeX for plot labels
Merge pull request #4872 from juliantaylor/backports-1.9

Backports stuff from master to 1.9
Merge pull request #4874 from juliantaylor/masked-sort-memory

ENH: avoid meshgrid and fancy indexing for 1d masked sort, for 1.9
Merge pull request #4878 from nouiz:doc
Merge pull request #4891 from juliantaylor/reduce-float-axis

DEP: deprecate float as axis argument to reductions, for 1.9
Merge pull request #4882 from pv/fix-unpickle-latin1-crash

BUG: core: fix crash when unpickling data on Py3 under non-latin1 encoding
Merge pull request #4883 from pv/fix-scalar-unpickle-py3

ENH: core: add hack enabling unpickling Py2 pickled scalars on Py3 under encoding='latin1'
Merge pull request #4892 from rgommers/msvc10-fix

BLD: fix build issues with MSVC10 on Windows.  Closes gh-4245.
Merge pull request #4888 from pv/fix-bytes-encoding-unpickle

ENH: core: make unpickling with encoding='bytes' work
Merge pull request #4889 from juliantaylor/object-array-init

BUG: initialize object array of array on resize and zeros
Merge pull request #4866 from mhvk/ma/mvoid-initialisation

BUG Masked recarray assignment with [row][record] does not work
Merge pull request #4887 from ewmoore/conj_obj

BUG: object array np.conjugate, ndarray.conjugate inconsistent
Merge pull request #4908 from juliantaylor/win-alignment

TST: win32 also does not provide 16 byte alignment, for 1.9
Merge pull request #4906 from juliantaylor/doc-update

documentation updates for 1.9
Merge pull request #4910 from seberg/scalar-none-cmp

BUG: None comparison deprecation does not affect scalars