Add the memory swappiness tuning option to docker.

Memory swappiness option takes 0-100, and helps to tune swappiness
behavior per container.
For example, When a lower value of swappiness is chosen
the container will see minimum major faults. When no value is
specified for memory-swappiness in docker UI, it is inherited from
parent cgroup. (generally 60 unless it is changed).

Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>

docs/reference/commandline/create.md

@@ -57,6 +57,7 @@ Creates a new container.
       --privileged=false         Give extended privileges to this container
       --read-only=false          Mount the container's root filesystem as read only
       --restart="no"             Restart policy (no, on-failure[:max-retry], always)
+      --memory-swappiness=""     Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100.
       --security-opt=[]          Security options
       -t, --tty=false            Allocate a pseudo-TTY
       -u, --user=""              Username or UID

docs/reference/commandline/run.md

@@ -58,6 +58,7 @@ weight=1
       --read-only=false          Mount the container's root filesystem as read only
       --restart="no"             Restart policy (no, on-failure[:max-retry], always)
       --rm=false                 Automatically remove the container when it exits
+      --memory-swappiness=""     Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100.
       --security-opt=[]          Security Options
       --sig-proxy=true           Proxy received signals to the process
       -t, --tty=false            Allocate a pseudo-TTY