client_write() proto and defines added

};

typedef struct send_buffer send_buffer;

#define CLIENTWRITE_BODY   1

#define CLIENTWRITE_HEADER 2

#define CLIENTWRITE_BOTH   (CLIENTWRITE_BODY|CLIENTWRITE_HEADER)

CURLcode client_write(struct UrlData *data, int type, char *ptr,

                      size_t len);

send_buffer *add_buffer_init(void);

CURLcode add_buffer(send_buffer *in, void *inptr, size_t size);

CURLcode add_bufferf(send_buffer *in, char *fmt, ...);