Cross-platform changes to onos.initd

We now can use start-stop-daemon (debian), daemon()
shell function (centos), or sudo (others) to start
onos-service.

It should be backward compatible on systemd systems.

Tested on Ubuntu 14 and CentOS 6. Should also work on
Ubuntu 15/16, CentOS 7, Debian, and Fedora.

(Note that we should test this against various OSes,
preferably automatically rather than manually!)

Addresses at least part of ONOS-2907

Change-Id: I4ded98baf02321a5a9db37fdff19e1ce4a3d23d2
diff --git a/tools/test/bin/onos-config b/tools/test/bin/onos-config
index e37dc3b..a38191d 100755
--- a/tools/test/bin/onos-config
+++ b/tools/test/bin/onos-config
@@ -37,7 +37,7 @@
 # ONOS builtin apps and providers ignited by default
 export ONOS_APPS="${ONOS_APPS:-drivers,openflow}"
 
-ssh $remote "
+ssh -tt $remote "
     echo \"onos.ip = \$(sudo ifconfig | grep $ONOS_NIC | cut -d: -f2 | cut -d\\  -f1)\" \
         >> $ONOS_INSTALL_DIR/$KARAF_DIST/etc/system.properties