pickle support ?

[asmodehn]

Basically trying to pickle a signature pickle.dumps(signature(my_func)) leads to :

File "/usr/lib/python2.7/pickle.py", line 1374, in dumps
    Pickler(file, protocol).dump(obj)
  File "/usr/lib/python2.7/pickle.py", line 224, in dump
    self.save(obj)
  File "/usr/lib/python2.7/pickle.py", line 306, in save
    rv = reduce(self.proto)
  File "/usr/lib/python2.7/copy_reg.py", line 77, in _reduce_ex
    raise TypeError("a class that defines __slots__ without "
TypeError: a class that defines __slots__ without defining __getstate__ cannot be pickled

It would be useful to be able to serialize function signatures. Although I don't know what python 3.X does about this and if this is in the scope of funcsigs to implement this...