output/Internal: hide Configure() and remove the non-configuring constructor

src/output/Init.cxx

@@ -49,19 +49,15 @@
 #define AUDIO_OUTPUT_FORMAT	"format"
 #define AUDIO_FILTERS		"filters"
 
-AudioOutput::AudioOutput(const AudioOutputPlugin &_plugin)
+AudioOutput::AudioOutput(const AudioOutputPlugin &_plugin,
+			 const ConfigBlock &block)
 	:plugin(_plugin)
 {
 	assert(plugin.finish != nullptr);
 	assert(plugin.open != nullptr);
 	assert(plugin.close != nullptr);
 	assert(plugin.play != nullptr);
-}
 
-AudioOutput::AudioOutput(const AudioOutputPlugin &_plugin,
-			 const ConfigBlock &block)
-	:AudioOutput(_plugin)
-{
 	Error error;
 	if (!Configure(block, error))
 		throw std::runtime_error(error.GetMessage());

src/output/Internal.hxx

@@ -282,8 +282,6 @@ struct AudioOutput {
 	 */
 	bool current_chunk_finished;
 
-	AudioOutput(const AudioOutputPlugin &_plugin);
-
 	/**
 	 * Throws #std::runtime_error on error.
 	 */
@@ -292,8 +290,10 @@ struct AudioOutput {
 
 	~AudioOutput();
 
+private:
 	bool Configure(const ConfigBlock &block, Error &error);
 
+public:
 	void StartThread();
 	void StopThread();
 

src/output/plugins/SolarisOutputPlugin.cxx

@@ -60,10 +60,6 @@ struct SolarisOutput {
 	explicit SolarisOutput(const ConfigBlock &block)
 		:base(solaris_output_plugin, block),
 		 device(block.GetBlockValue("device", "/dev/audio")) {}
-
-	bool Initialize(const ConfigBlock &block, Error &error_r) {
-		return base.Configure(block, error_r);
-	}
 };
 
 static bool