Update to 2.3.0
    
    - Update translations from zanata (de, ja, uk updated)
    - Commit the current preëdit when the focus changes
    - When preëdit empty or lookup table not enabled by key: clear the lookup table
    - Make key bindings configurable
      (Resolves: https://github.com/mike-fabian/ibus-typing-booster/issues/15)
    - Correct tooltips for the “up” and “down” buttons for
      input methods dictionaries