Fixes for Unicode and CJK characters

The 2.x version of pygprint used str() where it should use unicode(). This meant it couldn't be used with Unicode strings.

I also replaced a couple of list comprehensions with generator expressions because I think it's stylistically better, but it's not really a big deal.

An unrelated question: why isn't pygcurse available through PyPI so you can just do "pip install pygcurse"? :)