+* _ping:_ returns a success response
+* _init:_ initializes backend, looking for an active local UPnP server
+* _list:_ returns list of audio files, as a JSON structure
+* _select:_ select an audio files, by index number (001-...)
+* _play:_ plays the currently selected audio file
+* _stop:_ stops the currently selected audio file
+* _pause:_ pauses the currently selected audio file
+* _seek:_ seeks in the currently selected audio file, in seconds
+* _upload:_ uploads an audio file, with a POST request