bug fixed on "=-" symbol not proccssed
1. Add include guard

2. Add reading config.ini for user settings. The config will be loaded
every time the keyboard is opened.
3. Add conifg settings for candidate font size.
4. Add maxCodes user settings and dobeep when composition codes exceed.
5. Separate CanddiateHandler from UIPresenter.
Finish the notify window showing chinese/english full/half shape when switching