Run the 2to3 ws_comma fixer on *.py files. Some lines are now too long
and will need to be broken at some point. OTOH, some lines were already
too long and need to be broken at some point. Now seems as good a time
as any to do this with open PRs at a minimum.

Now is as good a time as any with open PR's at a low.

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.

The numarray and oldnumeric modules are deprecated. This is a bit tricky
as raising a DeprecationWarning on import causes an error when tests are
run. To deal with that, a ModuleDeprecationWarning class is added to
numpy and NoseTester is modified to ignore that warning during testing.

Closes #2905

The idioms fixer makes the following replacements.

1) int <- bool
2) comparison or identity of types <- isinstance
3) a.sort() <- sorted(a)

There were two problems that needed to be dealt with after the
application of the fixer. First, the replacement of comparison or
identity of types by isinstance was not always correct.  The isinstance
function returns true for subtypes whereas many of the places where the
fixer made a substitution needed to check for exact type equality.
Second, the sorted function was applied to arrays, but because it treats
them as iterators and constructs a sorted list from the result, that is
the wrong thing to do.

Closes #3062.

The numliterals fixer replaces the old style octal number like '01' by
'0o1' removes the 'L' suffix.

Octal values were previously mistakenly specified in some dates, those
uses have been corrected by removing the leading zeros.

Simply Removing the 'L' suffix should not be a problem, but in some
testing code it looks neccesary, so in those places the Python long
constructor is used instead.

The 'long' type is no longer defined in Python 3. Because we need to
have it defined for Python 2 it is added to numpy/compat/np3k.py where
it is defined as 'int' for Python 3 and 'long' for Python 2. The `long`
fixer then needs to be skipped so that it doesn't undo the good work.

Closes #3074, #3067.

In Python3 `dict.items()`, `dict.keys()`, and `dict.values()` are
iterators. This causes problems when a list is needed so the 2to3 fixer
explicitly constructs a list when is finds on of those functions.
However, that is usually not necessary, so a lot of the work here has
been cleaning up those places where the fix is not needed. The big
exception to that is the `numpy/f2py/crackfortran.py` file. The code
there makes extensive use of loops that modify the contents of the
dictionary being looped through, which raises an error. That together
with the obscurity of the code in that file made it safest to let the
`dict` fixer do its worst.

Closes #3050.

Add `print_function` to all `from __future__ import ...` statements
and use the python3 print function syntax everywhere.

Closes #3078.

The `imports` fixer deals with the standard packages that have been
renamed, removed, or methods that have moved.

cPickle      -- removed, use pickle
commands     -- removed, getoutput, getstatusoutput moved to subprocess
urlparse     -- removed, urlparse moved to urllib.parse
cStringIO    -- removed, use StringIO or io.StringIO
copy_reg     -- renamed copyreg
_winreg      -- renamed winreg
ConfigParser -- renamed configparser
__builtin__  -- renamed builtins

In the case of `cPickle`, it is imported as `pickle` when python < 3 and
performance may be a consideration, but otherwise plain old `pickle` is
used.

Dealing with `StringIO` is a bit tricky. There is an `io.StringIO`
function in the `io` module, available since Python 2.6, but it expects
unicode whereas `StringIO.StringIO` expects ascii. The Python 3
equivalent is then `io.BytesIO`. What I have done here is used BytesIO
for anything that is emulating a file for testing purposes. That is more
explicit than using a redefined StringIO as was done before we dropped
support for Python 2.4 and 2.5.

Closes #3180.

The new import `absolute_import` is added the `from __future__ import`
statement and The 2to3 `import` fixer is run to make the imports
compatible. There are several things that need to be dealt with to make
this work.

1) Files meant to be run as scripts run in a different environment than
files imported as part of a package, and so changes to those files need
to be skipped. The affected script files are:

    * all setup.py files
    * numpy/core/code_generators/generate_umath.py
    * numpy/core/code_generators/generate_numpy_api.py
    * numpy/core/code_generators/generate_ufunc_api.py

2) Some imported modules are not available as they are created during
the build process and consequently 2to3 is unable to handle them
correctly. Files that import those modules need a bit of extra work.
The affected files are:

    * core/__init__.py,
    * core/numeric.py,
    * core/_internal.py,
    * core/arrayprint.py,
    * core/fromnumeric.py,
    * numpy/__init__.py,
    * lib/npyio.py,
    * lib/function_base.py,
    * fft/fftpack.py,
    * random/__init__.py

Closes #3172