Report if LARGE FILE supported

vtlcmd -V
mktape -V
will both report if LARGEFILE support is enabled

Allow easier trouble-shooting for >4G files on 32bit platforms

Signed-off-by: Mark Harvey <markh794@gmail.com>
MAM: Comment each grouping of MAM attributes

Signed-off-by: Mark Harvey <markh794@gmail.com>
vtlcart: Fix 'checkpatch' coding style update

Signed-off-by: Mark Harvey <markh794@gmail.com>