Add onstart/onstop config option
The onstart and onstop options can be set in the configuration file to run a command when the audio playback is about to begin or has ended.
The full path for the command has to be specified, e.g. '/usr/bin/logger'.
Executable scripts must begin with a shebang, e.g. '#!/bin/sh'.
Signed-off-by: Jörg Krause joerg.krause@embedded.rocks
Authored by: Jörg Krause 2015-05-19
Parent(s): [6caa6e]
Child(ren): [0bc5d0][665b22]
