* the dictionary loader now supports word frequencies
* word frequency validation upon building
* added default word frequencies to all dictionaries
* updated documentation
* Settings screen is now based on the Android SharedPreferences
* Added function key configuration on the Settings screen
* Added a setting for toggling the on-screen buttons
* Added a dark/light theme setting
* Improved translations
* Fixed a problem with launching the Settings screen directly from the Android settings
* Fixed ignoring keys not actually ignoring them properly
