BF: doctest output difference workarounds

We were getting trivial doctest failures from format differences; see:
http://nipy.bic.berkeley.edu/builders/dipy-bdist32-32/builds/2/steps/shell_4/logs/stdio
Merge pull request #179 from matthew-brett/py3-doctest-fixes

BF: doctest output difference workarounds.
BF: fix python 3 doctest in fvtk

Missed a print statement in the doctest.
BF: fix Cython TypeError from negative indices to tuples

It looks as though Cython now raises a TypeError if you use negative indices
with the boundscheck decorator, even if these indices are to tuples.

Use positive indices instead.
Merge pull request #180 from matthew-brett/cython-indexing-fix

BF: fix Cython TypeError from negative indices to tuples
DOC: replace soureforge.net links with nipy.org

Change canonical nipy web address.
Merge pull request #185 from matthew-brett/no-sourceforge-links

DOC: replace soureforge.net links with nipy.org
NF: new model added for constrained spherical deconvolution and a corresponding test. This is still in progress
TEST updated test for test_csdeconv
cdeconv class returns a fit object
Started example for csd
Updated csd to work with any odf_sphere
TEST updated test2
NF: example with estimated response function from the data added
TEST: added module suite from numpy.testing
work in progress: need to debug odf_deconv
work in progress: need to debug odf_deconv
wip: debuging...
wip
wip