MEDIUM: cli: Add payload support

In order to use arbitrary data in the CLI (multiple lines or group of words
that must be considered as a whole, for example), it is now possible to add a
payload to the commands. To do so, the first line needs to end with a special
pattern: <<\n. Everything that follows will be left untouched by the CLI parser
and will be passed to the commands parsers.

Per-command support will need to be added to take advantage of this
feature.

Signed-off-by: Aurélien Nephtali <aurelien.nephtali@corp.ovh.com>
diff --git a/src/stream.c b/src/stream.c
index 2d8f278..1d0b22c 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -3025,7 +3025,7 @@
 }
 
 
-static int cli_parse_show_sess(char **args, struct appctx *appctx, void *private)
+static int cli_parse_show_sess(char **args, char *payload, struct appctx *appctx, void *private)
 {
 	if (!cli_has_level(appctx, ACCESS_LVL_OPER))
 		return 1;
@@ -3280,7 +3280,7 @@
 }
 
 /* Parses the "shutdown session" directive, it always returns 1 */
-static int cli_parse_shutdown_session(char **args, struct appctx *appctx, void *private)
+static int cli_parse_shutdown_session(char **args, char *payload, struct appctx *appctx, void *private)
 {
 	struct stream *strm, *ptr;
 
@@ -3315,7 +3315,7 @@
 }
 
 /* Parses the "shutdown session server" directive, it always returns 1 */
-static int cli_parse_shutdown_sessions_server(char **args, struct appctx *appctx, void *private)
+static int cli_parse_shutdown_sessions_server(char **args, char *payload, struct appctx *appctx, void *private)
 {
 	struct server *sv;
 	struct stream *strm, *strm_bck;