Multi duplicate session Set-Cookie header after 9e927c4 New ThreadedDict about webpy

[anandology]

Fixed mutliple set-cookie header issue with session. (closed by 23583b4)

The Session class was extended from ThreadedDict, which is extended from
threading.local. It looks like __init__ is called once for each thread
for thread local objects. That made session to add multiple processors
to the application, one for each thread/request.

Fixed this issue by keeping the threadeddict as an attribute instead of
extending from it.

[anandology]

chuangbo, can you please verify this fix?

[chuangbo]

Thanks!
I can't verify because I don't use session, but it seems to be ok.