lk 2.5.5-pre1 scsi_debug driver

The attachment will apply against lk 2.5.4 and
lk 2.5.5-pre1. Changes between version 1.57
and 1.58:
- replaces scatterlist::address references
- uses vmalloc for ram disk storage (used get_free_pages before)
- improves inquiry and mode sense support
- adds command tracing and crude error simulation

For a description of the driver see this page:
http://www.torque.net/sg/sdebug.html

Doug Gilbert