Correction of the Linux HTTP GET Bad Request (and more) :
 - correction of Session::decode(), it does not return anything now
 - HTTPPacketBuilding need now a shared_ptr<HTTPPacket> and does not have a link to a PoolBuffer anymore
 - HTTPSession : manage() doesn't pop anymore
 - Decoding : now there is ALWAYS ONE packetHandler for each buildPacket
 - Date : correction of usage of optional in udpate()
 - Moving FunctionalTests to a Flash client + added a test for HTTP bad requests