change some divisions to floordiv
replace builtin reduce() by functools.reduce()
trac #16371: reviewer patch - some PEP8 readability improvements
15545: do not use Cython var for unrelated purposes
15545: doctest
Merge branch 'develop' into t/15545/typeerror_in_matching_polynomial

* develop: (385 commits)
  Updated Sage version to 6.3.beta2
  avoid duplicate argument checking and documentation for %display
  fix docbuild due to backslash in output
  document the RIF comparison with infinity
  Reverts one doctest to old example, ignore last commit
  Reverted one example in doctest
  Removed trailing whitespace from last commit
  also accept %display typeset in ipython
  16199: documentation cosmetics
  Fix doctest failing on OS X on the last digit after upgarding numpy/scipy to 1.8.1/0.14.0
  trac #16387: expand doctest to also include initial and final states
  corrected spacings; extended one doctest
  added spaces after comment-symbol in code
  Trac 16224: add doctest
  updated examples from last commit
  Trac 11990: doctest for divergent sum error
  forbid conversion from unsigned infinity to RR, RDF
  fix addition/subtraction of unsigned infinity
  also add conversion (not: coercion) for CC -> infinity ring
  fixes and enhances hasse_invariant and hasse_invaraint__OMeara
  ...
Merge remote-tracking branch 'origin/develop' into py3_reduce

Conflicts:
	src/sage/categories/rings.py
Merge remote-tracking branch 'origin/develop' into py3_division

Conflicts:
	src/sage/graphs/generic_graph.py
15545: improve fix
Trac #15545: TypeError in matching_polynomial

{{{#!python
sage: G = Graph(10); G
Graph on 10 vertices
sage: G.matching_polynomial()
x^10
sage: G.add_vertex((0,1))
sage: G.matching_polynomial()
------------------------------------------------------------------------
---
TypeError                                 Traceback (most recent call
last)
<ipython-input-68-174221329fce> in <module>()
----> 1 G.matching_polynomial()

/Users/miller/sage-5.10/local/lib/python2.7/site-
packages/sage/graphs/matchpoly.so in
sage.graphs.matchpoly.matching_polynomial
(sage/graphs/matchpoly.c:2681)()

TypeError: an integer is required
}}}

Another victim of arbitrary vertex labels...

URL: http://trac.sagemath.org/15545
Reported by: rlm
Ticket author(s): Ralf Stephan
Reviewer(s): Nathann Cohen
Trac #16078: Python 3 preparation: reduce() is no more a builtin function

The Py2 builtin function {{{reduce()}}} is available in Py3 as
{{{functools.reduce()}}}.

The tool 2to3 adds {{{from functools import reduce}}}.

From the [[https://docs.python.org/2.7/library/functools.html#module-
functools||Python 2.7 documentation]]: [[br]]
functools.reduce(function, iterable[, initializer])[[br]]
This is the same function as reduce(). It is made available in this
module to allow writing code more forward-compatible with Python 3.
New in version 2.6.

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

URL: http://trac.sagemath.org/16078
Reported by: wluebbe
Ticket author(s): André Apitzsch
Reviewer(s): Wilfried Luebbe
Trac #16371: Change some integer divisions from / to //

The attached patch will simplify the transition to a python3 compatible
division semantic (see #15995)

URL: http://trac.sagemath.org/16371
Reported by: aapitzsch
Ticket author(s): André Apitzsch
Reviewer(s): Wilfried Luebbe