doc: add release notes for GlusterFS 3.5.3

Change-Id: Ic5a8be45f0397e492f56142856cf9bf9d35f91b5
BUG: 1125231
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/8903
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>