All manifests should use the old-master gperftools branch

We are going to be using a new branch of gperftools so we needed to
move the current master branch to a new branch called old-master. This
change updates the manifest files so that builds are not broken.

Change-Id: Ia0cab766004a91672bb3b89e762a25e6bee71ab8
Reviewed-on: http://review.couchbase.org/30646
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>