Reuse $('auth-submit') button
Cosmetic change for one-liner
Split setupAuthDialog() into multiple functions

- Call showAuthDialog() to avoid empty screen before mail parsing.
- Use setupSender/PasswordBox() to handle input fields.
- setupAuthDialog() is called back with sender object, as is.
Merge pull request #23 from tomyun/setupauth

초기화면 지연현상 방지