Fixed incorrect "Env vars" description in onos.sh.
Modified onos.sh so that ZooKeeper logdir can be configurable.
Fixed onos.py so that Hazelcast properly works.
 - Made onos_node.conf, hazelcast.xml and logback.xml to be specific for each instance.
Added note about Hazelcast config file to onos.properties.

Change-Id: I0fd3367fa38c0a7ee1b774977ca52e5202e02b04
diff --git a/conf/onos.properties b/conf/onos.properties
index 0f7256e..20d90c4 100644
--- a/conf/onos.properties
+++ b/conf/onos.properties
@@ -11,4 +11,5 @@
 net.floodlightcontroller.core.FloodlightProvider.workerthreads = 16
 net.floodlightcontroller.forwarding.Forwarding.idletimeout = 5
 net.floodlightcontroller.forwarding.Forwarding.hardtimeout = 0
-net.onrc.onos.core.datagrid.HazelcastDatagrid.datagridConfig = conf/hazelcast.xml
+# NOTE: Do NOT modify or remove the line below. This value will be overwritten by onos.sh script.
+net.onrc.onos.core.datagrid.HazelcastDatagrid.datagridConfig =