Bento builds are no longer supported, so remove references to that
built system.

This fixes the distutils built from an sdist (e.g. under tox),
without including _build_utils in binary distributions or the installed numpy.

The intention is to make it easier to spot missing items

The sub-package is already included in bento builds, it appears
to have been missed from distutils.

This fixes the following error whilst running any tests with tox

```
ImportError: No module named build_utils.apple_accelerate
```

This covers those locations that either import or build numarray
or numeric.

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.

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

Closes #3078.

This should be harmless, as we already are division clean. However,
placement of this import takes some care. In the future a script
can be used to append new features without worry, at least until
such time as it exceeds a single line. Having that ability will
make it easier to deal with absolute imports and printing updates.

New modules chebyshev and polynomial are added. The new polynomial module
is not compatible with the current polynomial support in numpy, but is much
like the new chebyshev module. The most noticeable difference to most will
be that coefficients are specified from low to high power, that the low
level functions do *not* accept the Chebyshev and Polynomial classes as
arguements, and that the Chebyshev and Polynomial classes include a domain.
Mapping between domains is a linear substitution and the two classes can be
converted one to the other, allowing, for instance, a Chebyshev series in
one domain to be expanded as a polynomial in another domain.

The new modules are not automatically imported into the numpy namespace,
they must be explicitly brought in with a "import numpy.polynomial"
statement.