Introduced command-line tool listpushusers to list currently active push users on this node.

Usage: listpushusers
-h,--help Prints a help text
-l,--login <arg> The optional JMX login (if JMX authentication is enabled)
-p,--port <arg> The optional JMX port (default:9999)
--responsetimeout <arg> The optional response timeout in seconds when reading data from server (default: 0s; infinite)
-s,--password <arg> The optional JMX password (if JMX authentication is enabled)
-t,--host <arg> The optional JMX host (default:localhost)