Fix a varios bugs in fapws3

[shigin]

• memleak in py_rfc1123_date;
• segfault if handler return type isn't list, file or iterator;
• proper handling the closing of a socket by client;
• add example of DoS client.

[william-os4y]

Thanks shigin for your cooperation.

Except the "do not segfault on wrong type", I'll merge your changes. Indeed, this one has also been corrected on my local repository (with a bit more changes).

I have to see how I can merge all your changes except that one ;-(.

William

[william-os4y]

merged in master.

Thanks for your contribution