MythMusic: hunt for tracks in the 'Music' storage group

This is just for testing and currently only looks on the master backend and
only if it wasn't found in the local music directory.

mythplugins/mythmusic/mythmusic/metadata.cpp

@@ -14,6 +14,7 @@
 #include <mythdownloadmanager.h>
 #include <mythlogging.h>
 #include <mythdate.h>
+#include <remotefile.h>
 
 // mythmusic
 #include "metadata.h"
@@ -686,7 +687,12 @@ QString Metadata::Filename(bool find) const
         return gMusicData->musicDir + m_filename;
 
     // maybe it's in our 'Music' storage group
-    //TODO add storage group lookup here
+    //FIXME: this is just looking on the master BE
+    QString filename = gCoreContext->GenMythURL(gCoreContext->GetSetting("MasterServerIP"),
+                                                gCoreContext->GetNumSetting("MasterServerPort"),
+                                                m_filename, "Music");
+    if (RemoteFile::Exists(filename))
+        return filename;
 
     // not found
     LOG(VB_GENERAL, LOG_ERR, QString("Metadata: Asked to get the filename for a track but no file found: %1")