[format] add large FAT32 support

* Based on fat32format from Ridgecrop Consultants Ltd:
  http://www.ridgecrop.demon.co.uk/index.htm?fat32format.htm
* Initial implementation by Tom Ehlert of DriveSnapshot:
  http://www.drivesnapshot.de/en/index.htm
* Closes #101

src/rufus.h

@@ -37,6 +37,7 @@
 #define MAX_LOG_SIZE                0x7FFFFFFE
 #define PROPOSEDLABEL_TOLERANCE     0.10
 #define FS_DEFAULT                  FS_FAT32
+#define LARGE_FAT32_SIZE            (32*1073741824LL)	// Size at which we need to use fat32format
 #define WHITE                       RGB(255,255,255)
 #define SEPARATOR_GREY              RGB(223,223,223)
 #define RUFUS_URL                   "http://rufus.akeo.ie"