Move jetty logging off of SLF4J and onto Neo4j standard logging.

This is a first step in moving off of the extensive set of xml and properties
files governing neo4j logging, and onto programmatic runtime controls.

In this commit, jettys default SLF4J logger is replaced with an adapter that
bridges jetty logging over to Neo4j. It also translates every jetty message
such that they no longer come from the jetty-namespaced packages, but from
org.neo4j.server.web.Jetty9WebServer. This is to highlight the fact that
jetty, in this context, is an internal component of Neo4j, and that its logging
should adhere to the logging specified by the org.neo4j.* scoped logging
configuration.
This system property here is also set in the jetty-logging.properties file below, included in the jar as a resource. Not both are necessary, we should pick one - i'd go for the properties file and have a comment in this class instead pointing to it.

Also, removing both these lines leads the LoggingIT to fail its assertion but it does not fail the build because i assume the assertion error is swallowed, even though it reaches the console. This is not necessarily a deal breaker but it'd be nice if it failed the build.