libcgroup: Better error reporting for libcgroup

libcgroup: Better error reporting for libcgroup

From: Ankita Garg <ankita@in.ibm.com>

This patch adds human readable error messages to the configuration parser.
The error lookup is implemented as a simple table, indexed by the error.

TODO: Save errno at ECGOTHER and pass it down as cgroup_lasterror.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ankita Garg <ankita@in.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
git-svn-id: https://libcg.svn.sourceforge.net/svnroot/libcg/trunk@228 4f4bb910-9a46-0410-90c8-c897d4f1cd53