Add wait flag to iptables

Fixes #1573
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Updated installation docs for CRUX as a Docker Host.

Docker-DCO-1.1-Signed-off-by: James Mills <prologic@shortcircuit.net.au> (github: therealprologic)
Update integration tests with --net flag
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Update using_supervisord.md

changed the version of ubuntu to 13.04. In latest sshd will not work.
Update ip test to parse new output
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #5998 from crosbymichael/iptables-wait

Add wait flag to iptables
Merge pull request #6015 from crosbymichael/update-test-flags

Update integration tests with --net flag
Add specific branch of jpetazzo's busybox to clone from so we can assume nice things about it

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Simplify "adduser" in the Dockerfile to use the more scripting-friendly "useradd"

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Added stats.go which provides strong types for all stats that will be exported by libcontainer. This commit only introduces the strong type.
Docker-DCO-1.1-Signed-off-by: Vishnu Kannan <vishnuk@google.com> (github: vishh)
Merge pull request #6019 from tianon/update-dockerfile-busybox

Add specific branch of @jpetazzo's busybox to clone from so we can assume nice things about it
now busybox as nc

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Add check for iptables xlock support
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #6022 from crosbymichael/iptables-wait

Add check for iptables xlock support
Merge pull request #6018 from vishh/stats_strongtype

Strong type all stats exported by libcontainer
Merge pull request #6020 from vieux/update_test_remove_nc_bind_mount

now busybox as nc
docs/reference/builder: fix USER doc

Docker-DCO-1.1-Signed-off-by: Johan Euphrosine <proppy@google.com> (github: proppy)
Merge pull request #6023 from proppy/patch-4

docs/reference/builder: fix USER doc
Merge pull request #6016 from ronsmits/patch-1

Update using_supervisord.md
Merge pull request #6006 from therealprologic/master

Updated installation docs for CRUX as a Docker Host.