* Moved Responder stuff to LLHTTPClient.
* Renamed LLHTTPClient::Responder to LLHTTPClient::ResponderWithResult.
* Deleted LLHTTPClientAdapter and LLHTTPClientInterface.
* Renamed AICurlInterface::TransferInfo to AITransferInfo and moved it
to llhttpclient.h
* Removed 'CURLcode code' argument from completed_headers.
Slightly more robust, adds one boolean to all responders, 99%
of which don't need that though, and an extra call redirection,
but well... We might need it this way when I add the possibility
to abort a transfer.
