libext2fs/e2fsck: refactor everyone who writes zero blocks to disk

Convert all call sites that write zero blocks to disk to use
ext2fs_zero_blocks2() since it can use Linux's zero out feature to do
the writes more quickly.  Reclaim the zero buffer at freefs time and
make the write-zeroes fallback use a larger buffer.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
debugfs: add allocate and set functionality to the bmap command

This also makes it easier test the ext2fs_bmap2() function.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
debugfs: fix build on systems that don't have gettext built-in

Debugfs (unlike all of the other programs in e2fsprogs) is not set up
to use translated strings.  So when building misc/plausible.c for
debugfs, we need to disable NLS.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
contrib: add support for COLLAPSE_RANGE and ZERO_RANGE to falocate program

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>