BUG: Make interp return NaN at NaN interpolation points.

A NaN interpolation point was interpreted as out of bounds on the left
side, hence the value of the left parameter in the function call was
returned.

>>> np.interp(np.nan, [-10, 10], [-2, 2])
-2.0

NaN is a better choice.

Closes #605.
MAINT: #2312, Make all tofile failures raise IOError.

Fix two that were raising ValueError instead.
Make some style cleanups.

Closes #2312.
DOC: Document tofile exception changes in 1.9.0 release notes.
BUG: get_info('openblas') does not read libraries key

The documented libraries tag in the site.cfg is not read by the configuration,
instead openblas_libs is used, this is inconsistent with atlas configuration.
So libraries first and then try openblas_libs for backward compatibility.

Also ensure check_libs returns None instead of a dict of empty lists if
nothing is found.
DOC: update openblas fork warning with fixed pthread build info
ENH: tril and triu broadcasting
DOC: triu/tril broadcasting release notes
Merge pull request #4364 from argriffing/triu-broadcasting

ENH: tril and triu broadcasting
TST: switch i386 build to python3.4 defaulting ubuntu 14.04

to do that fix a missing $DIST variable usage in the test script
Merge pull request #4361 from juliantaylor/py3.4-travis

TST: switch i386 build to python3.4 defaulting ubuntu 14.04
BUG: Fix promote_types, can_cast, as astype issues

- promote_types does not return correct string size for integer and string arguments. Fix so that integer and string types are promoted to string type that is long enough to hold integer type safely cast to string.
- can_cast incorrectly returns True for certain integer and string types. Fix so that can_cast only returns True if string type is long enough to hold integer type safely cast to string.
- calling astype to convert integer to string should fail if string type is not long enough to hold integer converted to string and casting argument is set to "safe".
BUG: Fixed issue 3504, and added tests for complex support
Merge pull request #3984 from ContinuumIO/promote_types_fix

Fix promote_types for strings and numbers
Merge pull request #4336 from Sankarshan-Mudkavi/fix-issue-3504

Fixed issue 3504
Merge pull request #4302 from charris/fix-gh-605

BUG: Make interp return NaN at NaN interpolation points.
Merge pull request #4333 from charris/fix-gh-2312

Fix gh 2312
Merge pull request #4191 from juliantaylor/openblas-info

BUG: get_info('openblas') does not read libraries key
Fix infinite recursion when initializing sub-class of array scalars.
Add test-case for multiple-inheritance on an array-scalar.
Merge pull request #4375 from ContinuumIO/fix_scalar_inherit

Fix scalar inherit