Projector: consolidate endpoint and dataport-client.

- dataport-client is folded into endpoint routine.
- fixed configuration parameters and test cases as well as well.
- dataport/client.go is ignored.
- only one connection with remote node.
- connection and transport is directly managed by endpoint.
- endpoint routine consolidated `reqch` and `kvch` into single `ch`.
- vbucket-routines will now close blocking endpoints based on configuration.

Change-Id: I9db8c2c1b032e9e9d5f81b45bb192059095bef22