replace Py2 file() builtin by open() builtin
replace file by io.IOBase
Simplifying the handling of blas for fflas-ffpack/linbox and make it more consistent across paltforms
Implement ComplexIntervalFieldElement.__nonzero__

In analogy to real interval field elements,
ComplexIntervalFieldElement.__nonzero__ now returns True if and only
if is not known to be exactly zero.
Disallow pari(None), improve docs for Strexpand()
Revert "replace file by io.IOBase"

in python 2, it is not equivalent

This reverts commit 0765f1f2429ea60c3a389c23d9c4cd57ce0b9542.
Trac #17087: Clean up fflas-ffpack and linbox

The packages fflas-ffpack and linbox work in tandem and have unnecessary
complex setup to deal with blas. This ticket aims to simplify the spkgs
by removing the useless bits and tidying the bits relating to blas.

URL: http://trac.sagemath.org/17087
Reported by: fbissey
Ticket author(s): François Bissey
Reviewer(s): Jean-Pierre Flori
Trac #16097: Python 3 preparation: Replace Py2 file() builtin by open() builtin

The Py2 builtin function {{{file()}}} is gone. It should be replaced
with the {{{open()}}} builtin function.

This ticket is tracked as a dependency of meta-ticket ticket:16052.

URL: http://trac.sagemath.org/16097
Reported by: wluebbe
Ticket author(s): André Apitzsch
Reviewer(s): Jeroen Demeyer
Trac #17105: Implement ComplexIntervalFieldElement.__nonzero__

In contrast to {{{RealIntervalFieldElement}}},
{{{ComplexIntervalFieldElement}}} did not implement {{{__nonzero___}}}.

{{{RealIntervalFieldElement.__nonzero__}}} returns {{{True}}} if it is
not known to be exactly zero.

This patch implements the same for {{{ComplexIntervalFieldElement}}}.

URL: http://trac.sagemath.org/17105
Reported by: cheuberg
Ticket author(s): Clemens Heuberger
Reviewer(s): Jeroen Demeyer
Trac #17119: Disallow pari(None)

Currently, `pari(None)` behaves like `pari("None")`, i.e. the monomial
of degree 1 in the variable `None`. Instead, we should raise an
exception for `pari(None)`.

Also clarify the docs of `Strexpand()` (which is how I found out about
this bug).

URL: http://trac.sagemath.org/17119
Reported by: jdemeyer
Ticket author(s): Jeroen Demeyer
Reviewer(s): Peter Bruin