Add exFat support

 * track our own Vold
 * track CM external_exfat & external_fuse

Change-Id: Icba610b5a2d6a7cfef0cd082da178cb93ccde354
Signed-off-by: houst0nn <houstonn@gmail.com>
Merge pull request #2 from AOSPA-legacy/kitkat

Add exFat support