Moved cbgb web/UI to port 8091 and stop serving NS web U/I.

Now there are 2 ports...

- 8091 - NS REST api (/pools) and cbgb's REST api (/_api)
  and cbgb's web UI (/_static).

- 8092 - Couch/CAPI REST api (/{db})

I'll remove the NS web U/I static assets in a later commit.
Remove NS static web UI assets (static-ns directory).