add button to restart to wifi configuration

SpiffsCookie.cpp

@@ -0,0 +1,43 @@
+#include "SpiffsCookie.h"
+#include "FS.h"
+#include "SPIFFS.h"
+
+SpiffsCookie::SpiffsCookie()
+{
+    if(!SPIFFS.begin(true))
+    {
+        Serial.println(F("SPIFFS Mount Failed"));
+    }
+}
+
+void SpiffsCookie::set()
+{
+    File file = SPIFFS.open("/cookie", FILE_WRITE);
+    if(!file)
+    {
+        Serial.println(F("- failed to open file for writing"));
+        return;
+    }
+
+    if(file.write('#'))
+    {
+        Serial.println(F("- file written"));
+    } else {
+        Serial.println(F("- write failed"));
+    }
+    file.close();
+}
+
+void SpiffsCookie::clear()
+{
+    if(!SPIFFS.remove("/cookie"))
+    {
+        Serial.println(F("Failed to remove file"));
+    }
+
+}
+
+const bool SpiffsCookie::isSet()
+{
+    return SPIFFS.exists("/cookie");
+}