[Python-Dev] Adding support for %U and %W for strptime in b2

http://www.python.org/sf/1045381 is a bug report about how strptime does nothing with %U and %W directives (week of the year with differences in whether Sunday or Monday starts the week). I just finished getting the algorithm to calculate the date given the year, either of %U or %W and the day of the week. Now the question is whether this is a bug fix or a feature implementation. If it is a bug fix I can check it right in. The only reason it wasn't in since the beginning is I didn't think of the day of the week being all you needed to figure out the date with %W or %U. If it is considered a feature, though, I will just add a note that %U and %W consume values but do nothing with them. So, what do you all think? -Brett