Very big changes to the structure, see detailed comment.

Introduced a dictionary class which can take a filename and an encoding
and load a dictionary into memory (at the moment only the edict2 dictionary
from Jim Breen).  Also introduced  mapping table of parts of speech to the
codes used in edict2, and can now succesfully strip the parts of speech
out and find their expanded explanations. extended the word class to have a
partsofspeech field as well.