ChangeLog, message.c, pass1b.c, pass2.c, pass3.c, problem.c, problem.h:

ChangeLog, message.c, pass1b.c, pass2.c, pass3.c, problem.c, problem.h:
  pass1b.c: Change routines to use PR_1B_BLOCK_ITERATE when reporting
  	problems rather than using com_err directly.
  problem.c, problem.h (PR_1B_BLOCK_ITERATE): Add new problem code.
  message.c (expand_percent_expression): Add safety check.  If ctx->str
  	is NULL, print "NULL" instead of dereferencing the null pointer.
  pass1b.c, pass2.c, pass3.c: Change calls to ext2fs_block_iterate to
  	ext2fs_block_iterate2, to support 64-bit filesizes and to speed things
  	up slightly by avoiding the use of the ext2fs_block_iterate's
  	compatibility shim layer.
version.h:
  Update for WIP release.