Description of problem: Tracker bug for 6.4
REVIEW: https://review.gluster.org/23062 (doc: Added release notes for 6.4) posted (#1) for review on release-6 by hari gowtham
REVIEW: https://review.gluster.org/23062 (doc: Added release notes for 6.4) merged (#3) on release-6 by hari gowtham