Check SD card before mounting

[foxbunny]

Currently, the init script for ORx's mount job looks like this:

mount_start() {
  if ! ismounted /mnt/sdcard; then
    /bin/mkdir -p /mnt/sdcard
    /bin/mount /dev/mmcblk0p1 /mnt/sdcard
  fi
  ....
}

fsck.fat should be performed on /dev/mmcblk0p1 before it is mounted. The mount command should use the errors=continue option so that the card is always mounted, even if it has errors.