vold: exFAT support

 * Add support for exFAT using FUSE implementation.

Change-Id: I590c7b1bc8fbcb8c0b2c669f4073ac022857e4da
vold: Add NTFS read+write support via ntfs-3g

 * Use ntfs-3g for full NTFS support.
 * Original code from Freescale.

Change-Id: I01191c3c339421904dc9415eb00143f7f8365152
Fix vold's use of readdir_r(3).

Change-Id: I805a1799755429dd1f6f3bdc2e6a02f483587b35