This patch finalizes the move from UTF-8 to a default encoding in the Python Unicode implementation. The internal buffer used for implementing the buffer protocol is renamed to defenc to make this change visible. It now holds the default encoded version of the Unicode object and is calculated on demand (NULL otherwise). Since the default encoding defaults to ASCII, this will mean that Unicode objects which hold non-ASCII characters will no longer work on C APIs using the "s" or "t" parser markers. C APIs must now explicitly provide Unicode support via the "u", "U" or "es"/"es#" parser markers in order to work with non-ASCII Unicode strings. (Note: this patch will also have to be applied to the 1.6 branch of the CVS tree.)