infinite recursion when patching class that implements __nonzero__

Version: mocker-1.1

Reproducer:

--------------------
import mocker

class O(object):
    def __init__(self, o):
        self._o = o

    def __nonzero__(self):
        return bool(self._o)

    @staticmethod
    def foo():
        return 'x'

m = mocker.Mocker()
mO = m.patch(O)

mO.foo()
m.result('bar')

m.replay()

x = O(1)
assert x.foo() == 'bar'
----------------

Result:

Traceback (most recent call last):
  File "break_mocker.py", line 23, in <module>
    assert x.foo() == 'bar'
  File "/usr/lib/python2.7/site-packages/mocker.py", line 2238, in __get__
    object = obj or cls
  File "break_mocker.py", line 8, in __nonzero__
    return bool(self._o)
  File "/usr/lib/python2.7/site-packages/mocker.py", line 2238, in __get__
    object = obj or cls
  File "break_mocker.py", line 8, in __nonzero__
    return bool(self._o)
  File "/usr/lib/python2.7/site-packages/mocker.py", line 2238, in __get__
    object = obj or cls
  File "break_mocker.py", line 8, in __nonzero__
    return bool(self._o)
  File "/usr/lib/python2.7/site-packages/mocker.py", line 2238, in __get__
    object = obj or cls
[...]
  File "break_mocker.py", line 8, in __nonzero__
    return bool(self._o)
  File "/usr/lib/python2.7/site-packages/mocker.py", line 2238, in __get__
    object = obj or cls
RuntimeError: maximum recursion depth exceeded

If the __nonzero__ method is removed from class 'O', the code works as expected.