moved compiled files to dist/
Added tests, reorganized repo

* Added tests
* Moved source code to src
* Moved languages to src/<lang>/
* Moved helper libraries to src/libs/
* Renamed unidecoder.js to basedecoder.js to reduce confusion between
  unihandecode.js and unidecoder.js
* Renamed Unidecoder to BaseDecoder to make it more obvious what it is
* Renamed pykakasi to jskakasi
* Moved data to src/ja/jskakasi/data/ as it's only used in jskakasi
* Removed unihandecode.data.min.js, this is now part of
  unihandecode.ja.min.js