Added long filename support.

Marlin/SdFatConfig.h

@@ -108,7 +108,14 @@ uint8_t const SOFT_SPI_SCK_PIN = 13;
  * a pure virtual function is called.
  */
 #define USE_CXA_PURE_VIRTUAL 1
+/**
+ * Defines for long (vfat) filenames
+ */
+/** Number of VFAT entries used. Every entry has 13 UTF-16 characters */
+#define MAX_VFAT_ENTRIES (2)
+/** Total size of the buffer used to store the long filenames */
+#define LONG_FILENAME_LENGTH (13*MAX_VFAT_ENTRIES+1)
 #endif  // SdFatConfig_h
 
 
-#endif
+#endif