ChangeLog, e2fsck.h, pass1.c, super.c:

ChangeLog, e2fsck.h, pass1.c, super.c:
  pass1.c (process_inode_cmp): Use EXT2_QSORT_TYPE to define the
  	appropriate return type for comparison functions for qsort.
  e2fsck.h: Add #ifdef protection for unistd.h
  super.c: Remove header files already included by e2fsck.h
ChangeLog, dblist.c, ext2fs.h:
  ext2fs.h: Define EXT2_QSORT_TYPE appropriately for the return type for
  	comparison functions for qsort.
  dblist.c (dir_block_cmp): Use EXT2_QSORT_TYPE in function declaration.
ChangeLog, extent.c:
  extent.c (ext2fs_create_extent_table): Use ext2fs_free_mem instead of
  	free().
  (extent_cmp): Use EXT2_QSORT_TYPE to define the appropriate return
  	type for comparison functions for qsort.