httpd: cgi-bin support for DELETE, PUT, OPTIONS etc methods

function                                             old     new   delta
handle_incoming_and_exit                            2217    2240     +23
static.request_POST                                    -       5      +5
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/0 up/down: 28/0)               Total: 28 bytes

Signed-off-by: Alexander Sack <asac@pantacor.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>