libcgroup: Improve parameter checking and usage in cgconfigparser

libcgroup: Improve parameter checking and usage in cgconfigparser

From: Sripathi Kodi <sripathik@in.ibm.com>

The following patch improves cgconfigparser's parameter checking and
usage(). It provides:

1) Support for long options. Not really needed now, but good to have.
2) Improved usage() functionality.

Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
git-svn-id: https://libcg.svn.sourceforge.net/svnroot/libcg/trunk@227 4f4bb910-9a46-0410-90c8-c897d4f1cd53