* Merge same characters of different dictionaries in search output.
* Transformation of reading search pattern, e.g. ka > か, か > カ, か > ka
  should be language independent.
* Implement advanced searching.
* Add modulized dictionary types.
  - CHISE?
* Asynchronous dictionary loading?
* Asynchronous searching?
* Prepare character data base.
* HMM! HMM!
* Write document.
* Implement partial match searching.
