output: return target id after successful add()

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
serve: attempt to find an available tuner before stopping this tuner if we need to change the channel

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
serve: attempt to find a tuner already tuned to the desired physical channel before searching for an available tuner #gklst

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>