cleaned up variables in device driver, delete in progress
TODO:
Delete
address the known issues for nosfs mbr update routines
(both are show stoppers for write operation)
Implement remaining HddDriver isr cases in this order:
delete, write, read
complete iProj 4
known issues:
nosfs.makeDirBlock doesn't handle file names too long
nosfs.makeFileBlock doesn't handle files that span blocks
defective functions in nosfs: get(Used/Free)(File/Fat)Blocks