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/

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

Justification:

Using backports for builtin functions allow for forward-compatibility and
speeds on newer python versions.

bin() is used heavily in decoded 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.

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

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