Split eubin.py into modules
Rename the class names: Agent -> Client
Overhaul maildir.py
Fix codes
Add __init__.py
Fix the codes to pass all the test cases!
Rename a file: __main__.py -> main.py
Modify relative import to absolute one
Renam function: getuid() -> _getuid()
Fix a bug
Rewrite main.py
Add some loggings for debugging purposes
Add a simple shell script as the entry point for eubin.