enable bit which is set appropriately and a per inode sparse disable
	bit which is preset on some system file inodes as appropriate.
      - Enforce that sparse support is disabled on NTFS volumes pre 3.0.
Signed-off-by: NAnton Altaparmakov <aia21@cantab.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!