* 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.