version 0.4
   * Enable to cut & paste text.
   * Enable to change keybind.
   * Add some functions ( SDLSKK_Context_clear_text etc. )

version 0.3
   * Enable to register word.
   * Enable to use minibuffer.
   * Change some behavior about key input.
   * Add some utility functions.
   * Enable to select character encoding in running.
   * Enable to use SJIS.

version 0.2
   * Change the interface of some functions.
   * Enable to save and load user dictionary.
   * Add simple error handling functions.
   * Some buf fix.

version 0.1
   First release