Log Message:
Update mikutter to 0.0.3.9.
While here, let to allow co-existence with ruby-escape package.

Improvements
* none
Fixes
* impossible to search with Japanese
* impossible to google search with Japanese
* fire shortcut key for tweet when typing search string
* memory leaks
* devours API with retrying tweet of keyed account that does not authenticat me
* not play sound on some platforms.