Added Folder preview for sounds

libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/SoundStreamHead2Tag.java

@@ -262,6 +262,11 @@ public class SoundStreamHead2Tag extends SoundStreamHeadTypeTag {
     public String toString() {
         return getName() + " (" + virtualCharacterId + ")";
     }
+    
+    @Override
+    public String getUniqueId() {
+        return "" + virtualCharacterId;
+    }        
 
     //getNeededCharacters intentionally not defined
     @Override

libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/SoundStreamHeadTag.java

@@ -272,6 +272,11 @@ public class SoundStreamHeadTag extends SoundStreamHeadTypeTag {
         return getName() + " (" + virtualCharacterId + ")";
     }
 
+    @Override
+    public String getUniqueId() {
+        return "" + virtualCharacterId;
+    }        
+
     //getNeededCharacters intentionally not defined
     @Override
     public void setSoundSize(boolean soundSize) {

libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/gfx/DefineExternalStreamSound.java

@@ -243,6 +243,11 @@ public class DefineExternalStreamSound extends Tag implements CharacterIdTag, So
     public String toString() {
         return getName() + " (" + virtualCharacterId + ")";
     }
+    
+    @Override
+    public String getUniqueId() {
+        return "" + virtualCharacterId;
+    }
 
     @Override
     public void getTagInfo(TagInfo tagInfo) {