upmpdcli: Add UPnP icon. Use procd for start/stop. 

Add uci config support for multiple instances

Signed-off-by: Ted Hess <thess@kitschensync.net>
These might be of interest:
https://github.com/medoc92/upmpdcli/blob/70cc428fd5edb4eb13c8f8f2b1979545d9398d27/src/upmpd.cxx#L501
https://github.com/medoc92/libupnpp/blob/master/libupnpp/upnpplib.cxx#L66