ChangeLog, badblocks.8.in, badblocks.c:

ChangeLog, badblocks.8.in, badblocks.c:
  badblocks.8.in: Added text explaining that the -n and -w options are
  	mutually exclusive.
  badblocks.c (usage): Fix usage message to make it clear that the block
  	count must be specified if the starting block is to be specified.
  	(The starting block should be a option, in the long run.)
  badblocks.c (test_nd): Save and restore the currently_testing variable
  	before going into the write verification loop.  This avoids a loop
  	termination problem if the last block on the disk is bad.  Also, turn
  	off the SIGALRM signal while restoring blocks after the user types ^C.
  	The num_saved variable is now static so that it won't get clobbered by
  	a longjmp.  buf_used and bb_count are no longer static, since they
  	aren't used by the cleanup routines anymore.
  badblocks.c (main): Removed an unsued varaible (buf_size).  Fixed bad
  	getopt argument that didn't allow the 'b' option to take an argument.
  	Added error checking when parsing the starting block number.  Fixed
  	lint warning in fscanf format string.