fix #24, using ww instead of IW

sql/apisub_views.sql

@@ -21,7 +21,7 @@ SELECT
 TO_CHAR(dbegin,'TMday FMDD TMmonth') AS normdbegin,
 CASE WHEN code<10 THEN '000'||code WHEN code>=10 THEN '00'||code END AS normcode,
 TO_CHAR(dbegin + duration-1,'TMday FMDD TMmonth') AS normdend,
-TO_CHAR(dbegin, 'ww') AS week,
+TO_CHAR(dbegin, 'IW') AS week,
 TO_CHAR(dbegin, 'yyyy') AS year,
 semester(dbegin) AS semester,
 COALESCE(countsub,0) AS nbsub,