Added example for 2D-histogram with variable bin size.
Fixed two typos.
ENH: added check for scalar array in get_ufunc_arguments from ufunc_object.c
Check if object is of array dimension zero, then avoid heavy calls like PyArray_FromAny. Hence passing obj to out_op PyArrayObject unchanged. Also PyArray_FromAny(obj,NULL,0,0,0,NULL) calls PyArray_FromArray(obj,NULL,0) which return original obj
ENH: added check for scalar array in PyArray_FromArray from ctors.c
Check if object is of array dimension zero with newtype is NULL. If so return it directly instead of checking for casting.
ENH: added check for scalar array in PyArray_FromArray from ctors.c
Check if object is of array dimension zero with newtype is NULL. If so return it directly instead of checking for casting.
ENH: added check for scalar array in PyArray_FromArray from ctors.c
Check if object is of array with newtype is NULL. If so return it directly instead of checking for casting.
ENH: added check for scalar array in PyArray_FromArray from ctors.c
Check if object is of array with newtype is NULL. If so return it directly instead of checking for casting.
ENH: check for the same object in can_cast_scalar_to from convert_datatype.c
Check if two dtypes references to the same object in can_cast_scalar_to from convert_datatype.c,
then the result is always OK
Merge pull request #3509 from arinkverma/gsoc_performance

ENH: added short path scalar array in get_ufunc_arguments from ufunc_object.c
MAINT: Remove outdated version checks.

Because Numpy 1.8.0 will no longer supports Python versions < 2.6 we
no longer need to check for that and can also remove the code that is
specific to those earlier versions.

To make this a bit safer, the toplevel setup.py file now contains a
check of the Python version number and raises an error when run by an
unsupported version.
MAINT: Use np.errstate context manager.

Now that Python < 2.6 is no longer supported we can use the errstate
context manager in places where constructs like
```
    old = seterr(invalid='ignore')
    try:
        blah
    finally:
       seterr(**old)
```
were used.
Merge pull request #3516 from charris/remove-outdated-version-checks

MAINT: Remove outdated version checks.
Merge pull request #3518 from charris/use-errstate-context-manager

MAINT: Use np.errstate context manager.
MAINT: Remove uses of the WarningManager class.

WarningManager was a workaround for the lack of the with statement
in Python versions < 2.6. As those versions are no longer supported
it can be removed.

Deprecation notes are added to WarningManager and WarningMessage, but
to avoid a cascade of messages in third party apps, no warnings are
raised at this time, that can be done later.

Closes #3519.
MAINT: Fix Python version dependent test.

The buffer test in numpy/core/tests/test_api.py was apparently
testing for incorrect behavior that was corrected in Python 2.7.5.
This PR changes the test to check for the correct results and makes
running it depend on Python version.

Closes #3512.
Merge pull request #3522 from charris/fix-test_api

MAINT: Fix Python version dependent test.
Update twodim_base.py
Merge pull request #3520 from charris/replace-warningmanager

Replace use of WarningManager by warnings.catch_warnings and then deprecate it.
Update twodim_base.py
Merge pull request #3531 from fkbreitl/master

Updated documentation for histogram2d() in twodim_base.py according to discussion