[atomic-devel] Add support for setting sysctls

[Daniel J Walsh <dwalsh redhat com>]

Merged into docker.

Not sure if it will show up in docker-1.11 or later.

This patch will allow you to set "Namespaced" sysctls in a docker 
containers.

man docker run
...
**--sysctl**=SYSCTL
  Configure namespaced kernel parameters at runtime

  IPC Namespace - current sysctls allowed:

  kernel.msgmax, kernel.msgmnb, kernel.msgmni, kernel.sem, 
kernel.shmall, kernel.shmmax, kernel.shmmni, kernel.shm_rmid_forced
  Sysctls beginning with fs.mqueue.*

  If you use the `--ipc=host` option these sysctls will not be allowed.

  Network Namespace - current sysctls allowed:
      Sysctls beginning with net.*

  If you use the `--net=host` option these sysctls will not be allowed.