public ConcurrentFilesystemTraverser(string rootDirectoryPath)
{
directories = new Stack <Tuple <DirectoryInfo, DirectoryFingerprint> > ();
files = new Queue <Tuple <FileInfo, DirectoryFingerprint> >();
// TBD: handle exceptions on root directory
DirectoryInfo di = new DirectoryInfo(rootDirectoryPath);
directories.Push(Tuple.Create <DirectoryInfo, DirectoryFingerprint>(di, null));
InitDirSkipList(rootDirectoryPath, ConfigFiles.GetDirectoriesFile());
InitFileSkipList(rootDirectoryPath, ConfigFiles.GetFilesIgnoreFile());
}