Fork OpenNMS to support asterisk-java 2.0 and PJSIP

OpenNMS ([login to view URL]) is an open source monitoring and systems management platform written in Java. It includes support to monitor SIP devices registered to and asterisk server and it does it by connecting to Asterisk's AMI interface and querying for SIP registrations. If the list of registrations change, OpenNMS generates an event or an alarm. OpenNMS depends on a old version of asterisk-java ([login to view URL]). We need to fork OpenNMS (stable version 23) to support asterisk-java master branch and it to be able to monitor PJSIP registered devices (This commit adds support for PJSIP devices: Ideally this fork of opennms should be submitted as a pull request to be incorporated into official opennms, but this is not mandatory.