fix(ngFilter): change week formatter in date filter to comply with ISO8601

Week formatter ("w" and "ww") in date filter was considering Sunday as the first day of the week.
To comply with ISO8601, this has been changed to Monday.

Closes #10314

Author: yannickadam

src/ng/filter/filters.js

@@ -273,7 +273,8 @@ function getFirstThursdayOfYear(year) {
 function getThursdayThisWeek(datetime) {
     return new Date(datetime.getFullYear(), datetime.getMonth(),
       // 4 = index of Thursday
-      datetime.getDate() + (4 - datetime.getDay()));
+      //ISO8601 mandates that a week starts on Monday. Making Sunday 7 instead of 0.
+      datetime.getDate() + 4 - (datetime.getDay() || 7));
 }
 
 function weekGetter(size) {

test/ng/filter/filtersSpec.js

@@ -235,7 +235,7 @@ describe('filters', function() {
     var noon =     new angular.mock.TzDate(+5, '2010-09-03T17:05:08.012Z'); //12pm
     var midnight = new angular.mock.TzDate(+5, '2010-09-03T05:05:08.123Z'); //12am
     var earlyDate = new angular.mock.TzDate(+5, '0001-09-03T05:05:08.000Z');
-    var secondWeek = new angular.mock.TzDate(+5, '2013-01-11T12:00:00.000Z'); //Friday Jan 11, 2012
+    var secondWeek = new angular.mock.TzDate(+5, '2013-01-13T12:00:00.000Z'); //Sunday Jan 13, 2013
     var date;
 
     beforeEach(inject(function($filter) {