Followup changes in JerryScript debugger after #1910.

* Remove 'jerry_debugger_cleaup'. Do it automatically in 'jerry_cleanup'.
* Updated the documentations.
* Updated the NuttX and Artik053 targets.

JerryScript-DCO-1.0-Signed-off-by: László Langó llango.u-szeged@partner.samsung.com

jerry-core/api/jerry.c

@@ -167,6 +167,13 @@ jerry_cleanup (void)
 {
   jerry_assert_api_available ();
 
+#ifdef JERRY_DEBUGGER
+  if (JERRY_CONTEXT (debugger_flags) & JERRY_DEBUGGER_CONNECTED)
+  {
+    jerry_debugger_close_connection ();
+  }
+#endif /* JERRY_DEBUGGER */
+
   for (jerry_context_data_header_t *this_p = JERRY_CONTEXT (context_data_p), *next_p = NULL;
        this_p != NULL;
        this_p = next_p)