Renamed test.py to reading tools and fixed for Python 3

The test.py file has been renamed as ReadingTools.py and has been fixed so
that it now works with Python3.  In the JapaneseSentenceDecoder.py file
we now use the ReadingTools.py functionality to tokenize the line
using mecab and to look up hiragana readings from Kakasi.
Small updates to files, no functional changes.
Change the lookups to look up by kanji or kana

Can now look up the definition of a word in either kanji or kana, if kanji
then the reading is passed as well and the definition is only returned if
both the kanji and the kana match.