Attached a patch. It changes OptimizedUnicode to be an alias for PyUnicode_Type and adds a note to the documentation for porters from 2.x that it has no effect on py3k.

The patch removes/refactors all OptimizedUnicode and allow_8bit_chars related obsolete code that had been left over from py3k transition. These removals/refactorizations have no operational effect, so the module still works the same way it has always worked in Py3k.

Should OptimizedUnicode be deprecated, too? In this case, it cannot be aliased to str, and _pysqlite_fetch_one_row() needs to raise a DeprecationWarning if OptimizedUnicode is used.