(cherry picked from commit cd29c50ca820a03b9cecb300a84fb884425cb565)

This commit is just code movement.
(cherry picked from commit 3a99114360636806078bbf614c241e89661bcc7f)

This was an upstream bug which we never encountered, and meanwhile
was fixed upstream by removing the conditional --enable-debug code.

This removes a fatal warning (-Werror) which stops compilation
on 32 bit machines.
(cherry picked from commit aa96881a512a144f4611a8e7c9801be9bb7ff9cf)

Previous commit 4df593496e116dfb635731c058b7627e81fc179c broke the
"file" command on logical volume paths, since these are symbolic
links.  We *should* follow these (only).

This inadvertantly broke virt-inspector too, which indicates that
we need more regression testing in this area.  Since carrying whole
Fedora images around could make the distribution even larger than
now, I'm not sure at the moment how to do this.

Thanks to Matt Booth for diagnosing this bug.

The file call can hang if called on char devices (because we are
using the file -s option).

This is hard to solve cleanly without adding another file API.

However this restricts file to regular files, unless called explicitly
with a /dev/ path.  For non-regular files, it will now return a
string like "directory".

There is a small semantic change for symbolic links.  Previously
it would not have worked at all on absolute links (or rather, the
results would have been undefined).  It would have treated relative
symlinks to regular files as the regular file itself.  Now it will
return the string "symbolic link" in both cases.

This commit also makes the API safe when called on untrusted
filesystems.  Previously a filesystem might have been set up so
that (eg) /etc/redhat-release was a char device, which would have
caused virt-inspector and virt-v2v to hang.  Now it will not hang.

  path = path to access file (/sysroot/.. or /dev/..)
  display_path = original path, saved so we can display it
  buf = optional buffer which is freed along return codepaths

There should be no change to the semantics of the code.

This also adds a regression test for VFAT and (conditionally)
NTFS filesystems.