libcgroup: New API interfaces for task placement

libcgroup: New API interfaces for task placement

From: Vivek Goyal <vgoyal@redhat.com>

Enhancement to libcg to do following.
- Parse the /etc/cgrules.conf file and place the task in the right cgroup.
- Exported two APIs which can place the task based on /etc/cgrules.conf
  or based on cgroup explicitly specified by the caller.

- There can be multiple users.
        - PAM module (pam_cgroup)
        - cgexec tool
        - cgclassify tool
        - APIs can be directly used by other cgroup aware user progarams.
        - Classification daemon

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
git-svn-id: https://libcg.svn.sourceforge.net/svnroot/libcg/trunk@136 4f4bb910-9a46-0410-90c8-c897d4f1cd53