fix DWIPath loading for songs that have a normal layout;

some DWI's have relative paths that don't begin with ".\
 Song.cpp

stepmania/src/RageLog.cpp

@@ -102,6 +102,7 @@ void RageLog::Warn( const char *fmt, ...)
 			"WARNING:  %s\n"
 			"/////////////////////////////////////////",
 			sBuff ); 
+	warnings.Add( sBuff );
 }
 
 void RageLog::Flush()