pickler: add some defensive code to _isfunction
pickler: add some defensive code to _isfunction

We were blindly assuming that all objects have a __class__
variable.  This might not be the case, so add some defensive
code to guard against objects w/out __class__.

Signed-off-by: David Aguilar <davvid@gmail.com>

git-svn-id: 93f2f39c93ae088b792869c1b97110104553f60a@34 ba5bf794-d048-0410-8f42-e1fdefefffeb

dongguangming/jsonpickle,mandx/jsonpickle,eoghanmurray/jsonpickle_prev,dongguangming/jsonpickle,mandx/jsonpickle,eoghanmurray/jsonpickle_prev,mandx/jsonpickle,mandx/jsonpickle,dongguangming/jsonpickle,dongguangming/jsonpickle