toolbox-version: grab only the commit hash instead of the commit message

This change prevent toolbox-version to keep too many lines when it updates
src/version.h, which was happening when the commit message contains the
word "commit".

Signed-off-by: Patrick Rouleau <pfrouleau@gmail.com>
Merge pull request #49 from pfrouleau/review/teach_toolbox-version_to_only_returns_the_commit_id

toolbox-version: grab only the commit hash instead of the commit message
Include the NTFS Boot Record backup in the cloned image

NTFS stores a copy of its Boot Record after the end of the volume, which is
1 block smaller than the partition. This commit updates the NTFS's totalblock
to include that block.

With this change, the md5sum of the restored floppy.raw is identical to
the md5sum of the cloned one.

Signed-off-by: Patrick Rouleau <pfrouleau@gmail.com>