Reduce the includes used in all files.

- To reduce the dependencies to the minimal the number of includes was
  reduced.

lib/include/mqtt_outbox.h

@@ -6,6 +6,7 @@
 #ifndef _MQTT_OUTOBX_H_
 #define _MQTT_OUTOBX_H_
 #include "platform.h"
+#include "esp_err.h"
 
 #ifdef  __cplusplus
 extern "C" {

lib/include/platform_esp32_idf.h

@@ -7,21 +7,9 @@
 #define _ESP_PLATFORM_H__
 
 #include "freertos/FreeRTOS.h"
-#include "freertos/task.h"
-#include "freertos/semphr.h"
-#include "freertos/queue.h"
 #include "freertos/event_groups.h"
 
-#include "lwip/err.h"
-#include "lwip/sockets.h"
-#include "lwip/sys.h"
-#include "lwip/netdb.h"
-#include "lwip/dns.h"
-
-#include "sys/queue.h"
-#include "esp_err.h"
-#include "esp_log.h"
-#include "esp_system.h"
+#include <sys/time.h>
 
 char *platform_create_id_string(void);
 int platform_random(int max);

lib/mqtt_outbox.c

@@ -5,8 +5,6 @@
 #include "esp_log.h"
 
 #ifndef CONFIG_MQTT_CUSTOM_OUTBOX
-
-
 static const char *TAG = "OUTBOX";
 
 typedef struct outbox_item {
@@ -151,7 +149,7 @@ esp_err_t outbox_set_tick(outbox_handle_t outbox, int msg_id, outbox_tick_t tick
         item->tick = tick;
         return ESP_OK;
     }
-    return ESP_FAIL; 
+    return ESP_FAIL;
 }
 
 esp_err_t outbox_delete_msgtype(outbox_handle_t outbox, int msg_type)

lib/platform_esp32_idf.c

@@ -1,9 +1,11 @@
 #include "platform.h"
 
 #ifdef ESP_PLATFORM
-#include "esp_system.h"
 #include "esp_log.h"
+#include "esp_system.h"
 #include <sys/time.h>
+#include <stdlib.h>
+#include <stdint.h>
 
 static const char *TAG = "PLATFORM";