Add various backports of Python 2.6 builtins: next(), any(), all(), bin()

This module contains four backports of Python 2.6 methods:
next() from Ross Brattain
any() from http://stackoverflow.com/questions/3785433/python-backports-for-some-methods
all() from http://stackoverflow.com/questions/3785433/python-backports-for-some-methods
bin() from http://code.activestate.com/recipes/576847/

These backports should be conditionally imported upon exception so they
do not shadow the builtin function on newer Pythons.

Example:

try:
    any([True])
except NameError:
    from autotest.client.shared.backports import any

Justification:

Using backports for builtin functions allows for forward-compatibility and
better performance on newer python versions.

bin() is used heavily when decoding hardware register bits.
any() and all() are useful for generators and list comprehensions
next() is useful because of the default argument, and it is consistent with
Python 3 usage.

v2: strip leading left zeros to match builtin bin()

Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>
backports_unittest: unit tests for backported any(), all(), bin(), next()

v2: test backports.bin against builtin bin for a larger range of numbers

Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>
import OrderedDict backport by Raymond Hettinger

http://code.activestate.com/recipes/576693-ordered-dictionary-for-py24/

Documentation:
http://docs.python.org/2/library/collections.html#collections.OrderedDict

Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>
import namedtuple backport by Raymond Hettinger

http://code.activestate.com/recipes/500261-named-tuples/

Documentation:
http://docs.python.org/2/library/collections.html#collections.namedtuple

Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>
import defaultdict backport by Jason Kirtland

http://code.activestate.com/recipes/523034-emulate-collectionsdefaultdict/

Documentation:
http://docs.python.org/2/library/collections.html#collections.defaultdict

Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>
collections: adjust namespace so names appear as
autotest.client.shared.backports.collection.namedtuple

v2: fixed whitespace

Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>