We have made big step towards C/R of LXC containers -- made support
for nested mount namespaces and addressed the re-attach issue. Also
we have AArch64 support merged.

Some work is still to be done, but it's good time to show what we
have so far, thus -- the 1.3-rc1.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>