disabled memory.js on debug build because it's slow
changed some sharding tests to handle auth #758

If a test starts a server by itself, it should use startMongodTest because that will add
the right options.  startMongodEmpty doesn't add them so the cluster will fail to auth.

fixes #758
Merge branch 'bugfixes/tokumx-1.3' into releases/tokumx-1.3