Addition of "--shm-size" to which size of /dev/shm is changed.

- Optional "--shm-size=" was added to the sub-command(run, create,and build).
- The size of /dev/shm in the container can be changed
  when container is made.
- Being able to specify is a numerical value that applies number,
  b, k, m, and g.
- The default value is 64MB, when this option is not set.
- It deals with both native and lxc drivers.

Signed-off-by: NIWA Hideyuki <niwa.hiedyuki@jp.fujitsu.com>

docs/reference/commandline/create.md

@@ -65,6 +65,7 @@ Creates a new container.
       --restart="no"                Restart policy (no, on-failure[:max-retry], always, unless-stopped)
       --security-opt=[]             Security options
       --stop-signal="SIGTERM"       Signal to stop a container
+      --shm-size=[]                 Size of `/dev/shm`. The format is `<number><unit>`. `number` must be greater than `0`.  Unit is optional and can be `b` (bytes), `k` (kilobytes), `m` (megabytes), or `g` (gigabytes). If you omit the unit, the system uses bytes. If you omit the size entirely, the system uses `64m`.
       -t, --tty=false               Allocate a pseudo-TTY
       -u, --user=""                 Username or UID
       --ulimit=[]                   Ulimit options