- Re-worked MODE SENSE/SELECT data structures into a linked list.
- Re-worked LOG SENSE/SELECT data structures into a linked list.
- Added support for sub-page MODE information.
- Added STK 9x40 drive emulations.
- Removed dead code from kernel driver.
- Add working REPORT DENSITY support to the SSC.
  This change required the personality modules to define the list of supported
  densities. The media density is defined at 'mktape' time.
  Hence, the optional 'media load' rules in device.conf are now redundent
  and not used.
  BUT: The option to load any media into any drive is also gone.

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