Changed the members of the Definition class to be instance variables rather
than global ones.  Extended the XML parsing to pick out all the important
parts of the edict definitions.

This was the problem with the XML parsing, because I had defined the variables
as class variables (i.e. static) instead of instance variables I was always
adding to the same lists instead of new ones, hence the problems I saw.  See
http://stackoverflow.com/questions/9946736/python-not-creating-a-new-clean-
instance