Add possibility to reset wifi credentials.

include/wordclock_constants.h

@@ -49,8 +49,9 @@ typedef enum
 #define PERIOD_TIME_VISU_UPDATE_US (1 * 1000 * 1000) // 1s
 #define TIMEOUT_LEDDIRECT_US (5 * 1000 * 1000)       // 5s
 
-#define SHORT_PRESS_US (100 * 1000)     // 100ms
-#define LONG_PRESS_US (2 * 1000 * 1000) // 2s
+#define SHORT_PRESS_US (100 * 1000)           // 100ms
+#define LONG_PRESS_US (2 * 1000 * 1000)       // 2s
+#define VERY_LONG_PRESS_US (10 * 1000 * 1000) // 10s
 
 // Current limit
 #define CURRENT_LIMIT_LED 2500 // limit the total current consumed by LEDs (mA)
@@ -65,5 +66,4 @@ typedef enum
 #define MATRIX_WIDTH 11
 #define MATRIX_HEIGHT 11
 
-
 #endif /* WORDCLOCK_CONSTANTS_H */