Add xTaskGetApplicationTaskTag() prototype.

Source/include/task.h

diff --git a/Source/include/task.h b/Source/include/task.h
index be76c20..859b0b6 100644
--- a/Source/include/task.h
+++ b/Source/include/task.h
@@ -957,6 +957,14 @@
 

 /**

  * task.h

+ * <pre>void xTaskGetApplicationTaskTag( xTaskHandle xTask );</pre>

+ *

+ * Returns the pxHookFunction value assigned to the task xTask.

+ */

+pdTASK_HOOK_CODE xTaskGetApplicationTaskTag( xTaskHandle xTask );

+

+/**

+ * task.h

  * <pre>portBASE_TYPE xTaskCallApplicationTaskHook( xTaskHandle xTask, pdTASK_HOOK_CODE pxHookFunction );</pre>

  *

  * Calls the hook function associated with xTask.  Passing xTask as NULL has