Apply a new rule to 'cgexec' command.

Apply a new rule to 'cgexec' command.

Hi,

Changelog of v6:
================
 * No change.

Changelog of v5:
================
 * Add the description of a new option "--sticky".

Changelog of v4:
================
 * Add a new option "--sticky" so that cgrulesengd daemon does not change
   the children's cgroups which is executed by 'cgexec' command.

Changelog of v3:
================
 * Set a SETUID to "cgexec" command file.
 * An euid is changed to the executing user from a root user.

Changelog of v2:
================
 * New patch.

Description:
============
This patch applies a new rule to 'cgexec' command.

cgroup_register_unchanged_process() is called so that cgrulesengd
daemon does not change the cgroup of a process, which is executed
by 'cgexec' command.
And cgroup_change_cgroup_flags() is called for applying a new rule.

Thanks
Ken'ichi Ohmichi

Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>