Merge branch 'upstream' into snapshot/ubuntu/precise
Update debian/gbp.conf for snapshot builds.
Refresh debian/patches after upstream merge.
Kludge deb format 3 snapshot build inadequacy.

@FIXME: For the 0.6.3 release.

This change should be in the 0005-Remove-userland-dist-rules.patch file but,
but dpkg-source cannot handle the diff from the latest release tarball to the
snapshot state.

Nota bene zfsonlinux/zfs#1775 -- bene orasse est bene studuisse.
Integrate libzfs_core changes.

The upstream libzfs package now provides a versioned libzfs_core library per
commit a6ce1eae54ca048ae7e7dfdcad05c5565a129226.

Rename libzfs1 to libzfs2 and libzpool1 to libzpool2 because packaging policy
stipulates that library package names should reflect the soname current number.
Update changelog for 0.6.2-2~precise~1.gbp8420db release