CBQE-0: minor improvements in membase_upgrade_win

Change-Id: Iee52720db19f9f791c9b716e47ff419398d313e6
Reviewed-on: http://review.couchbase.org/26828
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>
CBQE-0: comment com-->ent upgrade tests for old releases

Change-Id: I7d97c3a960930f02135cb4e6fa65af0897e8b06a
Reviewed-on: http://review.couchbase.org/26823
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>