onos-* script help functions, plus:

o support onos-watch on OS X by emulating 'watch'.

Change-Id: I072f347b21b038168e08405bd228434bcc421aeb
diff --git a/tools/test/bin/onos b/tools/test/bin/onos
old mode 100755
new mode 100644
index 89197db..780a90d
--- a/tools/test/bin/onos
+++ b/tools/test/bin/onos
@@ -3,6 +3,27 @@
 # ONOS remote command-line client.
 # -----------------------------------------------------------------------------
 
+function _usage () {
+cat << _EOF_
+usage:
+ $(basename $0) [-w] [node]
+
+flags:
+- -w : Waits for ONOS instance to reach run-level 100, i.e. to be fully started.
+
+options:
+- [node] : the node to attach to
+
+summary:
+ ONOS remote command-line client.
+
+ The -w flag depends on 'onos-wait-for-start'. If [node] is unspecified, \$OCI
+ is used.
+
+_EOF_
+}
+[ "$1" = "-h" ] && _usage && exit 0
+
 [ ! -d "$ONOS_ROOT" ] && echo "ONOS_ROOT is not defined" >&2 && exit 1
 . $ONOS_ROOT/tools/build/envDefaults
 . $ONOS_ROOT/tools/test/bin/find-node.sh