Add function to send command to devices

[Zananok]

I tried this:
action_cmd.attrib['mime'] = ('vnd.logitech.harmony/vnd.logitech.harmony.engine?holdAction')
cmd = 'type=IRCommand:deviceId=19594158:command=PowerToggle:status=press:timestamp=0'

but im not exactly sure how to separate the data

Got some info from here:
https://github.com/jterrace/pyharmony/blob/master/PROTOCOL.md