Install new man page for 'edit_tape'

Signed-off-by: Mark Harvey <markh794@gmail.com>
Update spec file for new 'edit_tape' utilities

Signed-off-by: Mark Harvey <markh794@gmail.com>
mhvtl.spec: Update for 1.4-6_release

Fix segfault in vtltape -> position_blocks_back()
Fix TAPE CAPACITY log page info

New utility 'edit_tape' to update virtual media 'metadata'

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