IBM lin_tape driver support

At this time, we don't recommend to use IBM lin_tape driver for LTFS (with the lin_tape tape backend). In the future, lin_tape suport code will be removed.

To use it, you need to add --enable-lintape option as an argument of configure script and build the tree. Also, you need to add DEFAULT_TAPE=lin_tape if you set the lin_tape tape backend as default tape backend.