Fixes,TCs for user/account operation by non super_admin users

This commit does following:
1.New functions in Utils based on CLI
2.Fixes for existing suite
3.Test cases for non super_admin users doing user/account operations

I tried to cover most of the possible test cases that can be duducted
from the swauth dev guide and swuath user role matrix.These resources
can be found here:
https://raw.github.com/rbeede/swauth/master/doc/source/Draft%20Security%20Guide/swift_swauth_roles_matrix.png
http://gholt.github.io/swauth/dev/

Change-Id: I45d99252825b82008abb679cffcc980732c815ea
Signed-off-by: Pushpesh Sharma <psharma@redhat.com>
Reviewed-on: http://review.gluster.org/6676
Reviewed-by: Luis Pabon <lpabon@redhat.com>
Tested-by: Luis Pabon <lpabon@redhat.com>