Policy of XSY Prerequiste

[Moon Ho Hwang]

XSY has been using
1) odict which is ordered dictionary
2) pydot drawing toop which requires another library Graphviz

Since they are not really necessary to run XSY,
(1) I would comment out using odict()
but using hashdict() which is included in XSY
(2) However, XSY\GraphVizy is still using pydot. As long as we don't
use XSY\GraphVizy\GraphVizy.py class, we don't have to install pydot
as well as Graphviz.

--
Moon Ho Hwang
https://sites.google.com/site/moonhohwang/