REVIEW: Jetty config cleanup

Following on @jdillon work to allow jetty config files as app parameters, this pull:

- makes any useful example jetty config as valid for the app parameter use case
- makes request logging enabled by default
- makes the rotated log file names for request.log and nexus.log be consistently named
- removed any out of date examples as noted
- uses logback-access request log impl so that request logs are rolled gzipped ( Jetty request log impl can't do this )
- further improved JMX config
- replaced deprecated ${property} notation with xml <Property />
- removed duplicate jetty.xml

Questions:

Request logging enabled by default ok?

jetty additional config ok as peer to jetty.xml? Should it be under 'etc' instead?

rotated log files as gz instead of zip? Windows users can't gunzip without additional install.

I left jetty-kitchen-sink.xml as a drop in replacement for jetty.xml in case tweaking wrapper.conf was not desired.ok?