a patch for Japanese messages

Attached:

Thanks for your patch, I have applied it with r22330.

For your information:

3 messages of 1641 are not translated to ja, but exist in en:

• enotif_impersonal_salutation
• enotif_anon_editor
• undeleterevdel

6 messages of 1647 in ja don't use some variables while en uses them:

• pagecategories
• cascadeprotected
• cascadeprotectedwarning
• revdelete-selected
• logdelete-selected
• protect-cascadeon