Wrappers around Kodi Python API for seamless Python 2/3 compatibility

Wrappers around Kodi Python API that normalize handling of textual and byte strings in Python 2 and 3. all GPL v.3 https://forum.kodi.tv/showthread.php?tid=327883 https://github.com/romanvm/kodi.six icon.png 0.1.3: - Fix non-UTF-8 byte string decoding in Python 2.