[Security][Improvement] Remove user and password from logs

[ikwattro]

In some scenarios, logs are shared between multiple parties, for example when we have a central logging system using Kibana or running services on mesos dc/os.

For improving security of the neo4j servers, the user and password should be left out from the log lines.

Expected Behavior

Log outputs should not show neo4j user and password used.

Current Behavior

2017-02-21 17:16:48.087 DEBUG 26967 --- [nio-8080-exec-5] o.n.o.drivers.http.request.HttpRequest   : Thread: 32, request: POST http://neo4j:XXXX@neo4jServerIP:7474/db/data/transaction/commit HTTP/1.1

Maybe in some debugging scenarios, we could have the need to show the user and password used, for example in order to be sure of the exact value taken from environment variables.

So maybe this should be configurable.