Implementation of PEP 3101, Advanced String Formatting. Known issues: The string.Formatter class, as discussed in the PEP, is incomplete. Error handling needs to conform to the PEP. Need to fix this warning that I introduced in Python/formatter_unicode.c: Objects/stringlib/unicodedefs.h:26: warning: `STRINGLIB_CMP' defined but not used Need to make sure sign formatting is correct, more tests needed. Need to remove '()' sign formatting, left over from an earlier version of the PEP.