Various improvements and fixes (#131)

- Added a custom spinner using the Tactility logo
- Fix for crash in version logging
- Make file browsing less verbose in log
- Fix memory leak in FileUtils
- Fix bug when display brightness was set to 255: after reboot it would be set to 0
- Smaller boot logo (removed empty space)

Tactility/Source/lvgl/Spinner.h

@@ -0,0 +1,8 @@
+#include "lvgl.h"
+
+/**
+ * Create the Tactility spinner widget
+ * @param parent pointer to an object, it will be the parent of the new spinner.
+ * @return the created spinner
+ */
+lv_obj_t* tt_spinner_create(lv_obj_t* parent);