Provide more location options for Mock in startmock.sh

Change-Id: Ie5f464987a911b4ddc9db2d9b447d25ba6fd4f5e
Reviewed-on: http://review.couchbase.org/28090
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>