Return correct process pid for lxc

Fixes #2875
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Added Docker-PHP to the list of client libs

Docker-DCO-1.1-Signed-off-by: Geoffrey Bachelet <geoffrey.bachelet@gmail.com> (github: ubermuda)
Merge pull request #4488 from crosbymichael/return-correct-lxc-pid

Return correct process pid for lxc
Fix name parameter

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #4475 from ubermuda/patch-1

Added Docker-PHP to the list of client libs
Merge pull request #4510 from vieux/fix_param_doc

Fix name parameter
Remove the ghosts and kill everything
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #4509 from crosbymichael/kill-all

Remove the ghosts and kill everything
Ensure that native containers die with the parent
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Revert "libcontainer: Use pivot_root instead of chroot"

This reverts commit 5b5c884cc8266d0c2a56da0bc2df14cc9d5d85e8.

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Revert "libcontainer: Use MS_PRIVATE instead of MS_SLAVE"

This reverts commit 757b5775725fb90262cee1fa6068fa9dcbbff59f.

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #4511 from crosbymichael/ensure-native-containers-die

Ensure that native containers die with the parent
Merge pull request #4512 from crosbymichael/no-pivot-root

No pivot root because of ramdisk