GSWauth authentication to be based on SWauth

We are planning on creating a GlusterFS aware authentication
system for gluster-swift based on SWauth.

We forked from SWauth commit
41d36ebe160aa3346f6f45197fff0c80f38fde58

Change-Id: Ia28730d21e04fc8d9ce0cb317fc04d0d97583fca
Signed-off-by: Luis Pabon <lpabon@redhat.com>
Reviewed-on: http://review.gluster.org/6069