Add support for long UDF labels and check for old versions of mkudffs (#784533)

UDF label is stored in the Logical Volume Identifier which has space for
either 126 Latin1 or 63 UCS-2 characters.  For compatibility reasons
with older versions of blkid, the possibly truncated UDF label is also
stored in the Volume Identifier which only has space for 30 Latin1 or 15
UCS-2 characters.

Because versions of mkudffs prior to 1.1 damage the label if it contains
non-ASCII characters, make sure GParted does not call such versions of
mkudffs with a non-ASCII character label.

Bug 784533 - Add support for UDF file system