add DirSnapshotManager.is_syncro test
modify test for DirSnapshotManager.file_snapMd5:
add case for coverage improve
modify test for DirectoryEventHandler._is_copy:
add case for coverage improve
Add client_daemon function test:
get_abspath, get_relpath, load_config
fix DirSnapshotManager.save_timestamp for local variable update
add test for DirSnapshotManager.save_timestamp