Added the disconnect proto

CURLcode Curl_ftp(struct connectdata *conn);

CURLcode Curl_ftp_done(struct connectdata *conn);

CURLcode Curl_ftp_connect(struct connectdata *conn);

CURLcode Curl_ftp_disconnect(struct connectdata *conn);

size_t Curl_ftpsendf(int fd, struct connectdata *, char *fmt, ...);

struct curl_slist *curl_slist_append(struct curl_slist *list, char *data);

void curl_slist_free_all(struct curl_slist *list);

/* The kerberos stuff needs this: */

int Curl_GetFTPResponse(int sockfd, char *buf,

                        struct connectdata *conn,