RF: reduce boiler-plate.
ENH: Implementation of the Westin tensor stats.
PEP8
RF: Change the name to imply that this actually does something with the input.

Rather than just 'checking' it. Also, changed the order of operations to
'short-circuit' the shape-checking.
DOC: Reformat the citation.
RF: This function is superseded by read_bvals_bvecs.
Merge pull request #170 from arokem/westin_stats

Westin stats
Merge pull request #178 from arokem/io_gradients

RF: This function is superseded by read_bvals_bvecs.
RF: make setup.py and exts work with Python 3
RF: import reduce for Python 3 compatibility

reduce no longer in builtins for Python 3
RF: disable __init__ error for Python 3
RF: add six module for Python 3 compatibility
RF: refactor pkg_info for Python 3

Loading ConfigParser
RF: remove copies of nibabel functions in utils

dipy depends on nibabel now, so no need for the copies.
RF: remove use of string split for Python 3 compat

Replace string.split with split method of string.
RF: refactor viz subpackage for Python 3

Fix implicit relative import in __init__
Replace use of .next method with next builtin
Replace print statements
RF: Make urlopen compatible with python 3

Import from urllib.request on Python 3, urllib2 for Python 2
RF: make compatibility function for pickle loads

Pickle loads has to load pickles saved in Python 2.  Also, the import
has changed between the versions.
RF: use six to import cPickle for Python 3

cPickle moved into pickle in Python 3; use six to import it for both.
RF: named imports required in Python 3

Cannot do ``from .module import *`` in Python 3.