- Fixed a variety of issues surrounding rendering of Python code that

- Fixed a variety of issues surrounding rendering of Python code that
contains unicode literals.  The first is that the "quoted_name" construct
that SQLAlchemy uses to represent table and column names as well
as schema names does not ``repr()`` correctly on Py2K when the value
contains unicode characters; therefore an explicit stringification is
added to these.  Additionally, SQL expressions such as server defaults
were not being generated in a unicode-safe fashion leading to decode
errors if server defaults contained non-ascii characters.
fixes #243