Add option to turn on JSON pretty printing in monitor

Expaned '-mon' arg to allow a 'pretty=on' flag. This makes the
monitor pretty print its replies to easy human debugging / reading
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

monitor.c

@@ -351,7 +351,10 @@ static void monitor_json_emitter(Monitor *mon, const QObject *data)
 {
     QString *json;
 
-    json = qobject_to_json(data);
+    if (mon->flags & MONITOR_USE_PRETTY)
+	json = qobject_to_json_pretty(data);
+    else
+	json = qobject_to_json(data);
     assert(json != NULL);
 
     qstring_append_chr(json, '\n');

monitor.h

@@ -14,6 +14,7 @@ extern Monitor *default_mon;
 #define MONITOR_IS_DEFAULT    0x01
 #define MONITOR_USE_READLINE  0x02
 #define MONITOR_USE_CONTROL   0x04
+#define MONITOR_USE_PRETTY    0x08
 
 /* flags for monitor commands */
 #define MONITOR_CMD_ASYNC       0x0001

qemu-config.c

@@ -283,6 +283,9 @@ static QemuOptsList qemu_mon_opts = {
         },{
             .name = "default",
             .type = QEMU_OPT_BOOL,
+        },{
+            .name = "pretty",
+            .type = QEMU_OPT_BOOL,
         },
         { /* end of list */ }
     },

vl.c

@@ -1562,6 +1562,9 @@ static int mon_init_func(QemuOpts *opts, void *opaque)
         exit(1);
     }
 
+    if (qemu_opt_get_bool(opts, "pretty", 0))
+        flags |= MONITOR_USE_PRETTY;
+
     if (qemu_opt_get_bool(opts, "default", 0))
         flags |= MONITOR_IS_DEFAULT;