fix(datepicker): rename dateFormat to datepickerPopup in datepickerPopupConfig

Closes #1810

Author: rafbgarcia

src/datepicker/datepicker.js

@@ -296,7 +296,7 @@ angular.module('ui.bootstrap.datepicker', ['ui.bootstrap.position'])
 })
 
 .constant('datepickerPopupConfig', {
-  dateFormat: 'yyyy-MM-dd',
+  datepickerPopup: 'yyyy-MM-dd',
   currentText: 'Today',
   clearText: 'Clear',
   closeText: 'Done',
@@ -328,7 +328,7 @@ function ($compile, $parse, $document, $position, dateFilter, datepickerPopupCon
       };
 
       attrs.$observe('datepickerPopup', function(value) {
-          dateFormat = value || datepickerPopupConfig.dateFormat;
+          dateFormat = value || datepickerPopupConfig.datepickerPopup;
           ngModel.$render();
       });
 

src/datepicker/test/datepicker.spec.js

@@ -795,6 +795,26 @@ describe('datepicker directive', function () {
 
   });
 
+  describe('setting datepickerPopupConfig', function() {
+    var originalConfig = {};
+    beforeEach(inject(function(datepickerPopupConfig) {
+      angular.extend(originalConfig, datepickerPopupConfig);
+      datepickerPopupConfig.datepickerPopup = 'MM-dd-yyyy';
+
+      element = $compile('<input ng-model="date" datepicker-popup>')($rootScope);
+      $rootScope.$digest();
+    }));
+    afterEach(inject(function(datepickerPopupConfig) {
+      // return it to the original state
+      angular.extend(datepickerPopupConfig, originalConfig);
+    }));
+
+    it('changes date format', function() {
+      expect(element.val()).toEqual('09-30-2010');
+    });
+
+  });
+
   describe('as popup', function () {
     var inputEl, dropdownEl, changeInputValueTo, $document;