mhvtl.spec: Update for 1.4-7_release

- Bumped version to 1.4-7
- Add DLT7000/DLT8000 emulation
- Record 'last load' data in MAM
- New utility 'edit_tape' which will allow modificiation of media 'meta data'
- Prevent and log possibility of READ ELEMENT STATUS overflowing data buffer
- Set 'POWERON-RESET' if library re-configured via HUP signal
- Update 'minor' number from 'unsigned char' to 'unsigned int' which removes
 max number of device nodes at 256
- Rework READ ELEMENT STATUS - Simplify code and correct bug where incorrect
 byte count returned.
- Add 'support' for specifying 9x40 and DLT media via barcode suffix
- Update kernel module to prevent overflow if DEF_MAX_MINOR_NO reached.
- Update kernel module to allow up to 1024 minor numbers
- Update kernel module vers to 0.18.12, vers date 20130310-0
- off-by-one fix of compression mode page
- Fix 'READ POSITION' ssc op code
- Helper scripts for NetBackup added
 - drive_stats.pl (parse 'scsi_command' output and email on tape unload)
 - vlt_endeject_notify.pl (NetBackup Vault helper)

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