chg: depends on autoconf 2.61 instead of 2.65

So that good old lenny can autogen.
fix: crash when a uniq_proto can't be created

Because of lack of RAM or if it's been disabled.
fix: don't pretend to know which way is clt->srv in streambuf
fix: reset http state after incomplete HEAD

This is important to call http_parser_reset_phase between two headers
even if we do not change the state we are in (here we stay in HEAD
state) because this resets pkts counter and first TS.
fix: remove useless c2s_way in http parser
chg: do not report a body when Content-Length=0 to ease client job

Especially since the body would then be reported only after some more
payload is received.
fix: take care to destruct a synchronized waiting list in sync with its dual
chg: cosmetics