Added looping to BackgroundMusic

Vocaluxe/Base/CBackgroundMusic.cs

@@ -33,7 +33,7 @@ namespace Vocaluxe.Base
                 foreach (int i in _BackgroundMusicStreams)
                 {
                     CSound.Fade(i, CConfig.BackgroundMusicVolume, CConfig.FadeTime);
-                    CSound.Play(i);
+                    CSound.Play(i, true);
                 }
             }
         }

Vocaluxe/Lib/Sound/COpenALPlay.cs

@@ -146,6 +146,7 @@ namespace Vocaluxe.Lib.Sound
                 {
                     if (AlreadyAdded(Stream))
                     {
+                        _Decoder[GetStreamIndex(Stream)].Loop = Loop;
                         _Decoder[GetStreamIndex(Stream)].Play();                        
                     }
                 }

Vocaluxe/Lib/Sound/CPortAudioPlay.cs

@@ -130,6 +130,7 @@ namespace Vocaluxe.Lib.Sound
                 {
                     if (AlreadyAdded(Stream))
                     {
+                        _Decoder[GetStreamIndex(Stream)].Loop = Loop;
                         _Decoder[GetStreamIndex(Stream)].Play();                        
                     }
                 }