convert opennms-jetty to use a jetty.xml file instead of hand-coded init
honor (most) opennms.properties settings
Merge remote-tracking branch 'origin/1.12'

Conflicts:
	integration-tests/src/test/java/org/opennms/netmgt/config/WillItUnmarshalTest.java
	opennms-jetty/src/main/java/org/opennms/netmgt/jetty/JettyServer.java
	pom.xml