Removed the synchronisation between the CPU thread and the audio thread.

Added code to detect and resume from buffer underruns.
Disabled the ability to change the DPL2 option after the game has started.
Fixed a memory leak that occurred in the DPL2 decoder.
Fixed the OSX build.

Source/Core/DolphinWX/Src/ConfigMain.cpp

@@ -638,6 +638,7 @@ void CConfigMain::CreateGUIControls()
 	{
 		FrequencySelection->Disable();
 		BackendSelection->Disable();
+		DPL2Decoder->Disable();
 	}
 
 	// Create sizer and add items to dialog