title: carrot2 api not support japanese language
body: <p>I am trying to use carrot2 API to cluster documents in japanese language. It throws out this WARN:</p>
  
  <p>org.carrot2.text.linguistic.DefaultTokenizerFactory: Tokenizer for Japanese (ja) is not available. This may degrade clustering quality of Japanese content. </p>
  
  <p>Hence, the clustering process failed and all docs belong to "other topic" cluster. </p>
  
  <p>Is there any help to solve this problem? </p>
  
  <p>Thanks in advance.</p>