add .gitignore
add SKK Dictionary(S-jisyo)
add utility method: explode string
Add original SKK egine

feature:

 - Hirakana conversion
 - Input mode change(wip)
 - callback delegate if need

not yet:

 - other input mode(katakana, hankaku)
 - register word/user dict
Update flick keyboard

 - enable contextView
 - show candidate table view if need
fix bundle identifier to release